A motor vehicle includes an adjustable steering assistance. The adjustable steering assistance includes an evaluation unit for evaluating the grip of a road travelled, in which the extent of the steering assistance is variable as a function of the result of the road grip evaluation. The effectiveness of the steering assistance adjustment is due to the fact that the driver is accustom to the hand moment exerted on the steering wheel during steering, conventionally as a fixed relationship to the torque, which for steering the wheels of the motor vehicle has to be exerted thereon. Consequently, the lower the steering resistance the less road grip as a general rule. In that the extent of the steering assistance is varied, a road with less grip can thus be suggested to the driver in order to prompt him to a correspondingly careful driving style.

A vehicle is described for example in DE 10 2004 036 087 A1 which determines the current operating condition and the operating mode of the vehicle based on operational data. A control signal is sent to control units for adjusting functional components of the vehicle based on the current operating condition. In particular, control units for chassis and instruments can be switched over into a poor weather mode on the basis of data obtained from various sources in order to take into account reduced road grip in poor weather. In the poor weather mode, the chassis settings for example are to be adapted to a smooth road surface or the maximum speed restricted.
This approach produces the problem that a chassis setting which is harder because of the adaptation to the smooth road suggests to the driver a better grip of the road surface than corresponds to the facts, and because of this can tempt the driver into an unadapted driving style. An automatic restriction of the maximum speed can be perceived as an annoyance, in particular when the driver's estimation of the road grip does not coincide with the estimation by the evaluation device.

Motor vehicle with road evaluation device


A computer-implemented method for content-agnostic referencing of a binary data file, the method comprising: determining a length of the binary data file, the length comprising the number of bits of the binary data file; for the determined length, generating all permutations of data of the determined length; locating an index within the generated permutations, wherein the index is the starting position of the binary data file within the generated permutations; and using the length and the index to indicate the binary data file.

File referencing techniques generally require knowledge about the kind of data being stored in order to efficiently index the data in a file referencing system. Similarly, knowledge about the data at issue is also generally used in creating improved compression approaches to reduce data size for transmission, storage, and the like.
There exists a need in the industry to improve file referencing and data compression techniques to reduce the amount of data that must be stored and/or transmitted.

This patent is subject to a terminal disclaimer.

Method and system for content agnostic file indexing


The present invention relates to a process for the preparation of substantially pure nateglinide of formula (I), substantially free from the cis-isomer and L-enantiomer and preparation of enantiomerically pure nateglinide form B, directly from the hydrolysis of a (−)-N-(trans-4-isopropylcyclohexyl-1-carbonyl)-D-phenylalanine alkyl ester in a ketonic solvent or water or mixture thereof.

Nateglinide is a new class of antidiabetic drug developed jointly by Ajinomoto Co. Inc. and Hoechest Marion Russel of Japan. Its blood sugar lowering effect is rapid following oral administration, since it is short-acting, it prevents hypoglycemia between meals. Nateglinide is indicated to lower blood glucose in patients with type 2 diabetes, where hypoglycemia cannot be adequately controlled by diet, physical exercise and α-glucosaccharase inhibitors.
Nateglinide is chemically termed as (−)-N-(trans-4-isopropylcyclohexyl-1-carbonyl)-D-phenylalanine which is represented by the following formula (I).

Nateglinide was first disclosed in the U.S. Pat. No. 4,816,486 (RE34878).
US20060148902A1 describe hydrolysis of a nateglinide methyl ester in a mixture of water and toluene in the presence of phase transfer catalysts and KOH followed by addition of dilute HCl, filtration, and drying to afford Form B.
U.S. Pat. No. 7,208,622 describes a process in which trans-4-isopropylcyclohexane carbonyl chloride (i.e. a derivative of trans-4-isopropylcyclohexane carboxylic acid) is reacted with D-phenylalanine in the presence of a caustic solution followed by acidification in a mixture of water and acetone and crystallization at 58-72° C. which results in Form H of nateglinide.
Indian application 177/MAS/2003A discloses a process for preparing nateglinide comprising: condensation of D-phenyl alanine methyl ester with trans-4-isopropyl-cyclohexylcarboxylic acid chloride in the presence of a halo solvent such as chloroform and a base (TEA, triethylamine) followed by alkali metal hydrolysis in an alcoholic solvent such as isopropanol. The resulting nateglinide contains the cis isomer and the L-isomer in an amount <0.05%. However, on following the methodology as disclosed in examples 1 and 2, it was observed that, the L-isomer content does not go below 0.22%. This is due to the use of alkali metal hydroxide in the hydrolysis step at ambient temperature. Further, the use of isopropanol in example 2, yields isopropyl ester of nateglinide on acidification with hydrochloric acid. Further, excess D-phenyl alanine methyl ester may either lead to formation of dimeric impurity of formula (D)
during coupling reaction or remains as impurity in the nateglinide ester which needs to be removed by HCl washing prior to hydrolysis.
Indian application 2007/MUM/02380 discloses a process which involves treating an alkyl ester of D-phenylalanine or its acid addition salt with trans-4-isopropylcyclohexanecarboxylic acid halide under biphasic conditions in the presence of a base to give nateglinide alkyl ester, which is hydrolyzed to nateglinide having chiral purity 99.9-100.0%.
US20070043117A1 discloses a process for the preparation of chirally pure nateglinide G, whereby after alkaline hydrolysis of nateglinide alkyl ester, in the mixture of methanol-water; mineral acid is added in two portions such that, in first place mixture of nateglinide base and its alkali salt is isolated whereas in the next step chirally pure nateglinide base is isolated. Thus the process requires two steps to isolate chirally pure nateglinide. Further, the mixture of nateglinide base and it's alkali salt is sticky in nature and hence filtration takes prolong time.
Nateglinide preparation is also disclosed in U.S. Pat. No. 5,463,116, US2004014815A, US2003229249A and WO2008096373.
Most of the prior art methods use a combination of an alkali metal hydroxide and alcoholic solvents during hydrolysis of nateglinide and crystallization of nateglinide. The major drawback of using alcoholic solvents is that some of the nateglinide esterifies back to nateglinide alkyl ester. Further, nateglinide obtained by following the prior art process, is contaminated with cis-isomer, L-isomer, and/or N-(4-isopropyl benzoyl)-D-phenyl alanine (an ethyl analog of nateglinide and dimer impurity), hence repetitive purifications are required to obtain the purified product. This further, thus, reduces yield and purity of the product.
Therefore there is a need to develop a process for the synthesis of nateglinide that overcomes the problems of prior art and that which is simple, cost effective, non-hazardous and industrially viable.

Process for the preparation of nateglinide


A dynamic spinal implant utilizes cartilage bearing graft material in dynamic disc replacement and/or facet arthroplasty. Methods and apparatus for dynamic spinal implants incorporate bulk articular graft tissues derived from donor joint sources in human (allograft or autograft) or non-human (xenograft) tissue. The donor joint is preferably prepared as a biological dynamic spinal implant with articular cartilage as a bearing interface between adjacent bone surfaces that naturally articulate with respect to one another.

The spinal motion segment consists of a unit of spinal anatomy bounded by two vertebral bodies, including the two vertebral bodies, the interposed intervertebral disc, as well as the attached ligaments, muscles, and the facet joints. The disc consists of the end plates at the top and bottom of the vertebral bones, the soft inner core, called the nucleus and the annulus fibrosis running circumferentially around the nucleus. In normal discs, the nucleus cushions applied loads, thus protecting the other elements of the spinal motion segment. A normal disc responds to compression forces by bulging outward against the vertebral end plates and the annulus fibrosis. The annulus consists of collagen fibers and a smaller amount of elastic fibers, both of which are effective in resisting tension forces. However, the annulus is not very effective in withstanding compression and shear forces.
As people age the intervertebral discs often degenerate. This degeneration of the intervertebral discs may lead to degenerative disc disease. Degenerative disc disease of the spine is one of the most common conditions causing pain and disability in our population. When a disc degenerates, the nucleus dehydrates. When a nucleus dehydrates, its ability to act as a cushion is reduced. Because the dehydrated nucleus is no longer able to bear loads, the loads are transferred to the annulus and to the facet joints. The annulus and facet joints are not capable of withstanding the applied compression and torsional loads, and as such, they gradually deteriorate. As the annulus and facet joints deteriorate, many other effects ensue, including the narrowing of the interspace, bony spur formation, fragmentation of the annulus, fracture and deterioration of the cartilaginous end plates, and deterioration of the cartilage of the facet joints. The annulus and facet joints lose their structural stability and subtle but pathologic motions occur between the spinal bones.
As the annulus loses stability it tends to bow out and may develop a tear allowing nuclear material to extrude. Breakdown products of the disc and facet joint, including macroscopic chunks, microscopic particles, and noxious biochemical substances build up. These breakdown products stimulate sensitive nerve endings in and around the disc, producing low back pain and sometimes, sciatica. Affected individuals experience muscle spasms, reduced flexibility of the low back, and pain when ordinary movements of the trunk are attempted.
Degenerative disc disease is irreversible. In some cases, the body will eventually stiffen the joints of the motion segment, effectively re-stabilizing the discs. Even in the cases where re-stabilization occurs, the process can take many years and patients often continue to experience disabling pain. Extended painful episodes of longer than three months often leads patients to seek a surgical solution for their pain.
Several surgical techniques have been devised to attempt to stabilize the spinal motion segment. Some of these methods include: heating the annular region to destroy nerve endings and strengthen the annulus; applying rigid or semi-rigid support members on the sides of the motion segment or within the disc space; removing and replacing the entire disc with a non-flexible, articulating artificial device; removing and replacing the nucleus; and spinal fusion involving permanently fusing the vertebra adjacent the affected disc.
Until recently, spinal fusion has generally been regarded as the most widely used treatment to alleviate back pain due to degenerative disc disease. Most spinal fusion techniques utilize some form of rigid metal stabilizing mechanism, such as the BAK spinal cage, that fixes the mechanical relationship between the adjacent vertebra. Some investigational fusion devices similar to metal fusion cages are being manufactured from cortical bone. Two of these biological fusion devices are the PLIF Spacer, for posterior lumbar interbody fusion, and the FRA Spacer, for anterior lumbar interbody fusion.
While spinal fusion treatment is effective at relieving back pain, all discal motion is lost in the fused spinal motion segment. The loss of motion in the affected spinal segment necessarily limits the overall spinal mobility of the patient. Ultimately, the spinal fusion places greater stress on the discs adjacent the fused segment as these segments attempt to compensate for lack of motion in the fused segment, often leading to early degeneration of these adjacent spinal segments.
Current developments are focusing on treatments that can preserve some or all of the motion of the affected spinal segment. One of these methods to stabilize the spinal motion segment without the disadvantages of spinal fusion is total disc replacement. Total disc replacement involves removing the cartilaginous end plates between the vertebral bone and the disc, large portions of the outer annulus and the complete inner nucleus. If the entire disc is removed, typically an artificial prosthesis is placed in the disc space. Many of the artificial disc prosthesis currently available consist of a soft polymer to act as the nucleus. The soft polymer is interposed between two metal plates that are anchored or attached to the vertebral endplates. Examples of these layered total disc replacement devices are shown, for example, in U.S. Pat. Nos. 4,911,718, 5,458,643, 5,545,229 and 6,533,818, which are herein incorporated by reference.
An alternative to total disc replacement is nuclear replacement. Like the artificial disc prosthetics, these nuclear replacements are also inert, somewhat flexible, non-biological prosthetics. The procedure for implanting a nuclear replacement is less invasive than the procedure for a total disc replacement and generally includes the removal of only the nucleus and replacement of the nucleus with a prosthetic that may be malleable and provide cushioning that mimics a natural disc nucleus. Several of this disc replacement prosthetics utilize a hydrogel material because of the similarity of hydrogel to certain of the properties of a natural disc nucleus. Examples of the prosthetics used for nuclear replacement are shown, for example, in U.S. Pat. Nos. 4,772,287, 5,192,326, 5,919,235 and 6,726,721, which are herein incorporated by reference.
Although prosthetic devices have provided significant advances in the treatment of degenerative disc disease, almost all of these prosthetic devices suffer from the challenges of being non-biological devices. It would be desirable to provide for devices and techniques that can advance the treatment of degenerative disc disease without incurring the problems inherent in implanting a non-biological device.

Dynamic spinal implants incorporating cartilage bearing graft material


A method and system for communicating with at least one managed system located behind a firewall are provided. The system includes an agent computer, located behind a firewall, to communicate with the at least one managed system and a management system. The management system communicates with the agent computer to provide computer related services. The management system is located on an opposed side of the firewall and communicates an envelope including at least one executable task to the agent computer for communication to the managed system. The executable task may be included in a script and the agent computer may poll the management system to determine if there is an envelope for it to receive.

The deployment of computer systems in the workplace has become increasingly widespread, and computer systems have become indispensable tools for workers in most industries. The challenge of providing adequate management and support for such computer systems has paralleled this deployment. Organizations with more than a few computers may employ an Information Technology (IT) professional (e.g., an IT administrator) to manage computer systems and networks of the organization. An IT administrator is typically burdened with a large number of tasks and responsibilities relating to such computer systems and networks. For example, the IT administrator, and supporting staff, are typically responsible for the installation and set up of computer systems and networks within an organization, the upgrading and maintenance of installed computer systems, and responding to service requests from users within the organization.
Although technology has in recent years driven the cost of computer systems down, service and support costs continue to escalate. In addition, for an in-house IT administrator to install, maintain or upgrade software on multiple computers, the organization requires additional, relatively powerful, dedicated hardware and software on-site. This additional hardware and software results in increased costs even though it may only be used infrequently. To enhance security, the computers of the organization are typically located behind a firewall and, accordingly, the additional hardware is also located on-site behind the firewall.

Method and system for communicating with a managed system located behind a firewall


The threshold value for a normally-off junction FET is a low value. Accordingly, in a semiconductor driver circuit using the normally-off junction FET, there have existed such problems as high-accuracy voltage control, high-speed charging into an input capacitor, and misoperations. A semiconductor driver circuit which is the most suitable for the normally-off junction FET is proposed by applying the high-accuracy gate-voltage generation scheme based on a Zener diode, a reduction in the turn-on loss based on a speed-up capacitor, the connection of an inter-gate-source capacitor, and a misoperation-preventing circuit based on the source-terminal optimum implementation scheme.

The present invention relates to d drive circuit for switching device and a semiconductor driver circuit of a normally-off junction FET, and a semiconductor device using the same.
A wide band-gap semiconductor element, which employs a wide band-gap material such as silicon carbide (SiC), gallium nitride (GaN), or diamond, exhibits excellent characteristics as a switching element. Here, examples of such a wide band-gap semiconductor element are as follows: Junction FET (JFET), Static Induction Transistor (SIT), MEtal-Semiconductor Field Effect Transistor (MESFET), Hetero junction Field Effect Transistor (HFET), and High Electron Mobility Transistor (HEMT). Also, in the junction FET having normally-off characteristics, even if a malfunction of a circuit has occurred, e.g., even if a gate driver circuit has failed, the short-circuit and failure can be prevented.
The normally-off junction FET is represented by and is equivalent to an equivalent circuit in which a parasite diode is connected in parallel to an input capacitor between the gate and the source. On account of this fact, in the case of the junction FET which employs SiC, the threshold value for turning on the switching element becomes equal to about 2.5 V, which is a significantly low value. Accordingly, in the normally-off junction FET, there have existed problems such as high-accuracy voltage control, high-speed charging into the input capacitor, and misoperations.
The inter-gate-source characteristics of the junction FET become the forward-direction characteristics of the diode. On account of this fact, applying thereto a voltage which is higher than the rise-up voltage causes a large gate current to continue flowing. As a result, power consumption by the gate driver circuit has increased.
Also, the threshold value is low, and thus the large gate voltage cannot be applied thereto at the time of turn-on. On account of this fact, the input capacitor cannot be charged at a high speed. As a result, the turn-on loss has increased.
Also, the noise-resistant amount is small, and thus a possibility of giving rise to occurrence of the misoperations is high. As a result, there have occurred, e.g., the self turn-on phenomenon and a misoperation at the time of turn-off.
Moreover, in the conventional technologies disclosed in JP-A-2000-243905 and JP-A-2004-14547, the proposal has been made concerning a technique for preventing the misoperation due to the self turn-on phenomenon by connecting a capacitor between the gate and the source. No description, however, has been given regarding the misoperation at the time of turn-off. Also, the conventional technologies relate to a driver circuit that uses an IGBT (Insulated-Gate Bipolar Transistor) whose threshold value is higher as compared with the normally-off junction FET. Namely, no description has been given concerning a circuit for driving a low-threshold-value element with a low loss.


An ink status system for determining the status of a consumable supply of ink contained in an ink container. The ink status system includes a first conductor, disposed on a first wall of the ink container, being aligned with the first wall such that the consumable supply of ink contacts a decreasing portion of the first conductor during consumption thereof and an ink sensing circuit, coupled to the first conductor, generating a continuously variable ink level signal as a function of the decreasing portion of the first conductor being contacted by the consumable supply of ink during consumption thereof. The ink status system is used in a liquid ink printer to determine the amount of ink remaining in an ink tank or ink cartridge. A liquid ink printhead of the printer includes the necessary circuitry to generate a signal indicating the status of the ink which can include ink levels as well as ink types or colors.

An ink jet printer of the so-called drop on demand type has at least one printhead from which droplets of ink are directed towards a recording medium. Within the printhead the ink is contained in a plurality of channels in which energy pulses are used to cause the droplets of ink to be expelled, as required, from orifices or nozzles at the end of the channels.
In a thermal ink-jet printer, the energy pulses are usually produced by resistors, each located in a respective one of the channels and individually addressable by current pulses to heat and vaporize ink in the channels. A thermal energy generator, usually a resistor, is located in each of the channels, a predetermined distance from the nozzles. The resistors are individually addressed with a current pulse to momentarily vaporize the ink thereby forming a bubble which expels an ink droplet. As the bubble grows, the ink which bulges from the nozzles is contained by the surface tension of the ink as a meniscus. As the bubble begins to collapse, the ink remaining in the channel between the nozzle and the bubble moves towards the collapsing bubble, causing a volumetric contraction of the ink at the nozzle resulting in the separation of the bulging ink as a droplet. The acceleration of the ink out of the nozzle while the bubble is growing provides the momentum and velocity of the droplet in a substantially straight line direction towards the recording medium. Because the droplet of ink is emitted only when the resistor is actuated, this type of thermal ink jet printing is known as drop-on-demand printing. The channel is then refilled by capillary action which, in turn, draws ink from a supply container. Operation of a thermal ink jet printer is described in, for example, U.S. Pat. No. 4,849,774.
One particular form of thermal ink jet printer is described in U.S. Pat. No. 4,638,337. The described printer is of the carriage type and has a plurality of printheads each having its own ink supply cartridge mounted on a reciprocating carriage. The nozzles in each printhead are aligned perpendicularly to the line of movement of the carriage and a swath of information is printed on the stationary recording medium as the carriage is moved in one direction. The recording medium is then stepped perpendicularly to the line of carriage movement by a distance equal to the width of the printed swath. The carriage is then moved in the reverse direction to print another swath of information. Full width or page width linear arrays, in which the sheet is moved past a linear array of nozzles extending across the full width of the sheet, are also known.
The ink supply cartridge is typically a prepackaged, usually disposable item, having a sealed container holding a supply of ink and having attached thereto a printhead with a linear or matrix array of nozzles. The printhead is either permanently attached to the cartridge, in which case, the entire printhead/cartridge is disposed of, or the cartridge is without a permanent printhead, in which case, the cartridge is disposed of by itself. Generally, the printhead includes terminals to interface with an electronic controller of the printer; electronic parts in the printhead itself are associated with the ink channels in the printhead, such as the resistors and any electronic temperature sensors, as well as digital means for converting incoming signals for imagewise operation of the heaters. Typically, cartridges are purchased as needed by the consumer and used either until the supply of ink is exhausted or until the amount of ink in the cartridge becomes insufficient to maintain the back pressure of the ink to the printhead within the usable range.
While many liquid ink printers have no mechanism to determine the amount of ink remaining within an ink supply, it is desirable to provide an indicator or signal to a user indicating that the supply of ink has been exhausted or has been sufficiently depleted such that continued printing will provide unsatisfactory results. Known ink level sensing systems include providing an indication that the end of the ink supply has been reached, counting the number of ink droplets the printhead is instructed to print, and providing discrete levels of ink level sensing.
Various ink quantity or level sensing systems for determining the amount of ink remaining in an ink supply are illustrated and described in the following disclosures, which may be relevant to certain aspects of the present invention.
In U.S. Pat. No. 4,342,042 to Cruz-Uribe et al., an ink supply system for an ink jet printer including a primary ink supply source and a secondary ink supply reservoir is described. The secondary ink supply reservoir includes a thin flexible membrane which serves as the upper surface and expands or contracts depending upon the amount of ink present in the reservoir. A proximity device senses the movement of the flexible membrane to monitor the quantity of ink present in the reservoir.
U.S. Pat. No. 5,049,898 to Arthur et al., describes a disposable printing assembly including a memory element in which data characterizing the assembly can be stored. The data can characterize the identity of the assembly or one or more of its operational characteristics. A monitoring circuit counts the number of ink droplets the printhead is instructed to print. This count is related to the quantity of ink consumed by the printhead during a given printing task. The memory element on the printhead desirably has a datum thereon that indicates the relative quantity of ink remaining in the ink chamber.
U.S. Pat. No. 5,136,305 to Ims, describes an ink jet printer with ink supply monitoring means. The printer includes a replenishable ink cartridge and ink jet printhead mounted on a carriage for translation across a printing region. The replenishable ink cartridge contains an ink supply monitoring means using a thermistor and constant current circuitry to indicate when the cartridge should be resupplied with ink.
U.S. Pat. No. 5,289,211 to Morandotti et al., describes an ink detecting device which gives advance warning of the end of the ink in a reservoir or cartridge feeding an ink jet thermal printhead. A pair of electrodes that are emersed in a spongy, ink soaked body contained in the reservoir, are arranged in a region adjacent to a feed duct at which the spongy body has a higher capillarity than in remote regions. The electrodes are connected to a bridge circuit which measures the electrical resistance of the ink between the two electrodes.
U.S. Pat. No. 5,386,224 to Deur et al., describes a discrete ink level sensing system including a level sensing probe with at least first and second level sensing pads placed in an ink reservoir. The level sensing system uses electrical conductivity of the ink to detect when the upper surface level of the ink is lower than the lowest points of the level sensing pads.

Ink status system for a liquid ink printer


A brake apparatus capable of applying a regulator pressure regulated by a regulator valve device to an assisting chamber, to obtain a smooth brake feeling, even when a brake pedal is operated by a vehicle driver, during an automatic braking operation. A first control valve is disposed in a power pressure passage for controlling hydraulic pressure in the assisting chamber to be increased. A changeover valve device is disposed in a regulator pressure passage for selecting either one of a communicating state and a shutting-off state of the passage. A second control valve is connected to the regulator pressure passage between the changeover valve device and the assisting chamber, and controls the hydraulic pressure in the assisting chamber to be decreased.

The present invention relates to a brake apparatus for a vehicle, and more particularly to the apparatus capable of applying a regulator pressure regulated by a regulator valve device to an assisting chamber formed backward of a master piston.
In general, as for the brake apparatus capable of applying the regulator pressure to the assisting chamber formed backward of the master piston, it is disclosed in Japanese Patent No. 3101205, for example. That is, the brake apparatus includes a master piston, which is fluid-tightly slidably disposed in a cylinder body, to form a pressure chamber in front of the master piston and a power chamber behind it, and moved in response to operation of a manually operated braking member, to discharge a hydraulic braking pressure from the pressure chamber, an auxiliary hydraulic pressure source which pressurizes the brake fluid up to a predetermined pressure, and discharges a power pressure, a control piston which is fluid-tightly slidably accommodated in the cylinder body and arranged to be moved in response to movement of the control piston, and regulator valve means which introduces the power pressure discharged from the auxiliary hydraulic pressure source into a regulator chamber, to regulate the power pressure into a predetermined pressure in response to movement of the control piston. The hydraulic pressure regulated by the regulator valve means is applied to the power chamber of the master cylinder, to assist the operation of the manually operated braking member. With respect to the brake apparatus capable of applying the regulator pressure regulated by the regulator valve means to the power chamber (assisting chamber) as described above, Japanese Patent Laid-open Publication No. 11-180290 discloses hydraulic pressure relationships among various parts, in detail.
Recent vehicles require an automatic braking control, which is adapted to measure a distance or speed difference between a vehicle by a driver and another vehicle traveling ahead thereof to determine a necessity for decreasing the vehicle speed, and perform a braking operation automatically to decrease the vehicle speed, unless a vehicle driver operates an accelerator pedal, and which is called as "ACC" (abbreviation of "Adaptive Cruise Control"). And, a control apparatus which is capable of performing the automatic braking control is getting popular. During the automatic braking control operation as described above, when a vehicle driver operates a brake pedal, the automatic braking operation shall be cancelled, and shifted to the braking operation performed in response to operation of the brake pedal by the vehicle driver.
For example, Japanese Patent Laid-open Publication No. 2000-108859 proposes a braking control apparatus, which is aimed to perform the automatic braking operation, and cancel it, when it is detected that the brake pedal has been operated by a driver, and discloses an embodiment using a hydraulic booster as an actuator. According to this braking control apparatus, the vehicle can be braked automatically, so as to keep a certain distance between the vehicle driven by the driver and another vehicle traveling ahead thereof detected by a sensor, and can be braked to provide an emergent braking operation.
Also, Japanese Patent No. 3296235 proposes a braking force control apparatus, which is aimed to produce a hydraulic braking pressure larger than a normal pressure, when the emergent braking operation was performed by the vehicle driver, and reflect an intention of the vehicle driver on the hydraulic braking pressure, and which is capable of performing a so-called brake assist control. For example, there are provided an increased assisting pressure state for holing the hydraulic braking pressure larger than the normal pressure, and a decreased assisting pressure state for decreasing the hydraulic braking pressure irrespective of operation of the brake pedal.
As described in the Japanese Patent Laid-open Publication No. 2000-108859 or Japanese Patent No. 3296235, as for the automatic braking control apparatus for performing an automatic pressure increasing control as required, irrespective of operation of the brake pedal, to perform the braking operation automatically, various types of the apparatus have been known heretofore, so that their controlling state are different depending upon their objects, and their responses, which are taken when the automatic braking operation is shifted to the brake pedal operation by the vehicle driver, are different from each other. Particularly, in the case where the brake pedal is operated by the driver, in such a state that the braking operation is being performed, as a result of determination that the distance between the vehicle driven by the driver and another vehicle traveling ahead thereof has become to be smaller than a predetermined distance, for example, such as the above-described automatic braking control, it is desired that a smooth brake feeling shall be given to the driver.
However, according to the braking control apparatuses as disclosed in the Japanese Patent Laid-open Publication No. 2000-108859 or Japanese Patent No. 3296235, when the braking operation is shifted to the one operated by the brake pedal, there may be a case where the smooth brake feeling can not be expected. As described in paragraphs [0054] and [0055] of the Publication No. 2000-108859, for example, when the hydraulic pressure is fed from an accumulator to all of front and rear wheels, the brake pedal will hardly stroke, to provide a so-called "depressing board" state, which is inappropriate. Also, the Publication No. 2000-108859 discloses an embodiment, where the brake pressure shall not be supplied to a front wheel brake cylinder not to be controlled, during the automatic braking operation. According to this embodiment, the brake pressure will be supplied only to rear wheel brake cylinders, during the automatic braking operation, so that a desired braking operation may not be performed.
Furthermore, the braking control performed by the apparatus as described in Japanese Patent No. 3296235 is different from the braking control according to the present invention, which is performed by the braking control apparatuses as described in Japanese Patent No. 3101205 and Publication No. 11-180290, so that the relationships of the pressures in the braking control apparatuses are different from each other. Therefore, countermeasures as described in Japanese Patent No. 3296235 can not be employed, as they are. Particularly, while the brake assist operation is being performed in case of the emergent braking operation, the communication between the master cylinder and wheel brake cylinder is forced to be blocked, so that the "depressing board" feeling will be given to the driver. In order to avoid this, such a countermeasure as providing a so-called stroke simulator will be required.


A digital control device for tracking a sine wave according to the present invention has a compensator, a control object and a feedback gain. An input into the compensator is a signal obtained by subtracting a control quantity from a reference value. An input into the control object is a signal obtained by subtracting an output of the feedback gain from an output of the compensator. A transfer function of the compensator is (k2z+k1)/(z2−2z cos ωT+1), where ω is an angular frequency, T is a sampling period, z is a z operator, and k1 and k2 are constants. Thus, a second-order compensator can be configured, with which a sinusoidal reference waveform can be tracked simply and with high accuracy.

The output voltage waveform of voltage inverters for vector control of AC electric motors by large power voltage inverters is not a sine wave but a PWM modulated rectangular wave. Consequently, there is the problem of waveform distortion due to higher harmonics.
To address this problem, various devices for digitally controlling sine wave tracking have been proposed. FIG. 5 is a diagram showing the system configuration of such a digital control device for sine wave tracking. This digital control device is configured by a compensator, a control object, and a feedback gain (h). The compensator is provided for controlling the tracking of the output y[i] of the control object to a reference waveform yr[i].
Ordinarily, an integrator as shown in FIG. 6 is often used for the compensator in FIG. 5. However, even when performing compensation with this integrator, sine-wave tracking control is not possible, and deviations occur. With the control device in FIG. 6, when determining the gain by deadbeat control for a second-order control object, and trying to track a sine wave, a result as shown in FIG. 7 is obtained. The width between the two curves in FIG. 7 shows the deviation between the sinusoidal reference waveform and the control result with the control device in FIG. 6. FIG. 8 shows a graph in which the sample points of the initial portion 11 in FIG. 7 have been enlarged. As becomes clear from FIG. 8, a deviation occurs with the control device of FIG. 6.
On the other hand, there are also configurations provided with a compensator due to repetitive control as shown in FIG. 9, based on the internal principle model. However, with a compensator using this repetitive control, a configuration becomes necessary whose order corresponds to one cycle. Therefore, in order to control a 50 Hz sine wave with a sample time of 100 μS (microseconds), a compensator of the 200th order becomes necessary. It should be noted that the "200" of the "200th order" is calculated by "( 1/50)/0.0001)." An explanation of repetitive control is given for example in "KISO DIGITAL SEIGYO (Basic Digital Control)," Corona Publishing, p. 108.


RJ-45 style communications jacks include a housing having a plug receiving cavity, a guide protruding from a first surface of the housing into the plug receiving cavity and a stop provided at a second surface of the housing. The guide is configured to contact a plug housing of an RJ-11 communications plug when the RJ-11 communications plug is inserted within the plug receiving cavity so that the guide directs the RJ-11 communications plug toward the second surface where the stop prevents the RJ-11 communications plug from being fully inserted within the plug receiving cavity.

Many hardwired communications systems use plug-jack connectors to connect a communications cable to another communications cable or to a piece of equipment such as a computer, printer, server, switch or patch panel. By way of example, high speed communications systems routinely use such plug-jack connectors to connect computers, printers and other devices to local area networks and/or to external networks such as the Internet. FIG. 1 depicts a simplified example of such a hardwired high speed communications system that illustrates how plug-jack connectors may be used to interconnect a computer 1 to, for example, a network server 10.
As shown in FIG. 1, the computer 1 is connected by a cable 2 to a communications jack 5 that is mounted in a wall plate 9. The cable 2 is a patch cord that includes a communications plug 3, 4 at each end thereof. Typically, the cable 2 includes a plurality of wire conductors (e.g., eight), which are arranged in pairs so that each pair of conductors may carry a separate differential signal. Communications plug 3 inserts into a communications jack (not pictured in FIG. 1) provided in the back of the computer 1. Communications plug 4 inserts into an opening or "plug aperture" 6 in the front side of the communications jack 5 so that the contacts of the communications plug 4 mate with respective contacts of the communications jack 5 (if the cable 2 includes eight conductors, the communications plugs 3, 4 and the communications jack 5 will typically each have eight contacts). The communications jack 5 includes a wire connection assembly 7 at the back end thereof that receives a plurality of conductors (e.g., eight) from a second cable 8 that are individually pressed into slots in the wire connection assembly 7 to establish mechanical and electrical connections between each conductor of the second cable 8 and a respective one of a plurality of conductive paths through the communications jack 5. The other end of the second cable 8 is connected to a network server 10 which may be located, for example, in a telecommunications closet of a commercial office building. Thus, the patch cord 2, the cable 8 and the communications jack 5 provide a plurality of electrical paths (e.g., four differential signal paths) between the computer 1 and the network server 10. Each of these electrical paths may be used to communicate electrical information signals between the computer 1 and the network server 10. It will be appreciated that typically one or more patch panels or switches, along with additional communications cabling, would be included in the electrical path between the second communications cable 8 and the network server 10. However, for ease of description, these additional elements have been omitted from FIG. 1 and the second communications cable 8 is instead shown as being directly connected to the network server 10.
In order to provide standardization between the high speed communications equipment marketed and sold by different vendors, industry standards documents have been promulgated that specify various mechanical and electrical properties for communications jacks and plugs. One example of such a standard is the TIA/EIA-568-B.2-1 standard that was approved on Jun. 20, 2002 by the Telecommunications Industry Association. These industry standard documents typically incorporate, by reference, interface and wiring standards that specify, among other things, the dimensions and configurations of various types of standardized communications plugs and jacks so that industry standards-compliant plugs and jacks sold by different vendors will work with each other.
By way of example, the above-referenced TIA/EIA-568-B.2-1 standard requires compliance with interface specifications set forth in the FCC Part 68.500 document, which defines, among other things, the dimensions and configurations for various plug-jack interfaces, including plugs and jacks that conform to the Registered Jack 45 ("RJ-45") wiring standard and plugs and jacks that conform to the Registered Jack 11 ("RJ-11") wiring standard. The RJ-45 wiring standard describes wiring specifications for eight wire connector assemblies (including plugs and jacks) that are commonly used, for example, in Ethernet networks to connect computers and other hardware to local area networks (LAN) and/or the Internet, as is discussed above with respect to FIG. 1. The RJ-11 wiring standard, on the other hand, describes wiring specifications for four and six wire connector assemblies that are used in the United States primarily to connect telephone equipment. Herein, a plug or jack that substantially complies with the RJ-11 wiring standard is referred to as an "RJ-11" or "RJ-11 style" communications plug or jack, and a plug or jack that substantially complies with the RJ-45 wiring standard is referred to as an "RJ-45" or "RJ-45 style" communications plug or jack.
FIG. 2A is a simplified perspective view of an RJ-45 style communications jack 20, and FIG. 2B is a simplified plan view of an RJ-45 style communications plug 30. FIG. 4 is a perspective view of the RJ-45 style communications plug 30. As shown in FIG. 2A, RJ-45 jack 20 includes eight resilient jackwire contacts 21-28, which are mounted so that they extend into a plug receiving cavity 29. As shown in FIGS. 2B and 4, the RJ-45 communications plug 30 includes eight plug contacts 31-38, which are often referred to as "blades." The plug contacts 31-38 are received within contact slots 31′-38′ that are provided in the top surface of the housing 39 of RJ-45 communications plug 30 (each contact slot 31′-38′ also extends into the front surface of RJ-45 communications plug 30). The contact slots 31′-38′ on RJ-45 communications plug 30 are positioned so that when the plug 30 is inserted into RJ-45 communications jack 20, the contact slots 31′-38′ are aligned with plug contact regions of respective ones of jackwire contacts 21-28. Thus, when the RJ-45 communications plug 30 is inserted into the plug receiving cavity 29 of RJ-45 communications jack 20, the plug blades 31-38 make mechanical and electrical connection with respective ones of the jackwire contacts 21-28. The plug-jack interface is designed so that, as the plug 30 is inserted into plug receiving cavity 29, the blades 31-38 of the RJ-45 communications plug 30 engage their respective contacts 21-28 and deflect them back and/or upward a short distance. The resiliency of the jackwire contacts 21-28 creates a "contact force" that holds the jackwire contacts 21-28 in firm engagement with their respective plug blades 31-38. When the RJ-45 communications plug 30 is removed, the jackwire contacts 21-28 move downwardly and/or forwardly back into their normal resting position.
FIG. 3A is a simplified perspective view of a six contact RJ-11 communications jack 40, and FIG. 3B is a simplified plan view of a six contact RJ-11 communications plug 50. As shown in FIG. 3A, the RJ-11 communications jack 40 includes six jackwire contacts 42-47, which are mounted so that they extend into a plug receiving cavity 49. As shown in FIG. 3B, the RJ-11 communications plug 50 includes six plug contacts 52-57. The plug blades 52-57 are received within contact slots 52′-57′ on the top surface of the housing 59 of RJ-11 communications plug 50. The contact slots 52′-57′ on RJ-11 communications plug 50 are positioned so that when the plug 50 is inserted into RJ-11 communications jack 40, the contact slots 52′-57′ are aligned with plug contact regions of respective ones of the jackwire contacts 42-47. The RJ-11 communications plug 50 and jack 40 work together in the same manner, described above, that the RJ-45 communications plug 30 and jack 20 work together. An RJ-11 communications plug with four contacts does not contain contacts 52 and 57, but does include the contact slots 52′ and 57′. As the differences between four contact and six contact RJ-11 plugs are immaterial to this description, the remainder of this specification will focus on six contact RJ-11 communications plugs.
As is evident from FIGS. 2-4, RJ-45 connector assemblies (i.e., plugs and jacks) look very similar to RJ-11 connector assemblies, except that RJ-45 communications plugs and jacks are slightly wider than RJ-11 communications plugs and jacks and include at least two more contacts. Moreover, telephone and facsimile lines that are wired using RJ-11 style communications plugs and jacks are often located in the telecommunications closet of a building in close proximity to Ethernet equipment that is wired using RJ-45 plugs and jacks. Due to the visual similarities between the RJ-11 and RJ-45 connector assemblies, and their close proximity in many telecommunications closets, all too often, the slightly narrower RJ-11 communications plugs are inserted into RJ-45 communications jacks.
Unfortunately, when an RJ-11 communications plug is inserted into an RJ-45 communications jack, the RJ-45 communications jack can be damaged. This can best be seen with reference to FIG. 5, which is a cross-sectional diagram taken along line 5-5 of FIG. 4. As shown in FIG. 5, the vertical height of the housing 39 of plug 30 is about 0.260″. However, the plug blades 31-38 that are mounted in the contact slots 31′-38′ do not extend all the way to the top of housing 39. Accordingly, the effective height of the housing 39 along respective ones of the contact slots 31′-38′ is somewhat less (approximately 0.023″ less) than the height of the housing 39. The same is true with respect to the RJ-11 plug 50 of FIG. 3B, namely the height of the housing 59 of plug 50 is approximately 0.260″, while the distance from the top edge of each plug blade 52-57 to the bottom of the housing 59 is only about 0.237″.
When RJ-11 communications plug 50 is inserted into RJ-45 communications jack 20, the forward and top surfaces of the housing 59 of the plug 50 engage jackwire contacts 21 and 28 of jack 20, as the six blade RJ-11 communications plug 50 does not include contact slots or plug blades in the outside two contact positions (i.e., the major difference between the six contact RJ-11 communications plug 50 and the RJ-45 communications plug 30 is that the RJ-11 communications plug 50 does not include slots 31′ and 38′ and contacts 31 and 38 that are included on the RJ-45 communications plug 30). As the housing 59 of RJ-11 communications plug 50 (as opposed to contacts of plug 50), which has the full height of 0.260″, engages the outside jackwire contacts 21 and 28, the jackwire contacts 21 and 28 of jack 20 are over-deflected by 0.023″ when RJ-11 communications plug 50 is accidentally inserted into RJ-45 communications jack 20 (as compared to when an RJ-45 plug is inserted). Unless the jackwire contacts 21 and 28 of jack 20 are specially designed to accommodate this additional amount of deflection, the jackwire contacts 21 and 28 may become permanently set in this over-deflected position if RJ-11 communications plug 50 is inserted into RJ-45 communications jack 20 (i.e., the contacts lose some or all of their ability to spring back into their resting position). If this occurs, when an RJ-45 communications plug 30 is later inserted into the RJ-45 communications jack 20, the "contact force" needed to keep blades 31 and 38 of the RJ-45 communications plug 30 in abutment with the respective jackwire contacts 21 and 28 of the RJ-45 communications jack 20 may not be present (or may be insufficient), which may result in poor performance. When insufficient contact force is present, the RJ-45 communications jack 20 may also fail to pass certain tests in the industry standards such as, for example, a specified minimum contact resistance that must be maintained between each plug blade and its respective jackwire contact after a minimum number of plug insertions and removals and under various environmental conditions (e.g., temperatures, relative humidity, etc.).

RJ-45 style communications jacks having mechanisms that prevent an RJ-11 style communications plug from being fully inserted within the jack


A program executing apparatus includes a first storage section which stores data permitted to be leaked out; a second storage section which stores secret data of a user; a communication section which can communicate with an external unit; a program storage section which stores at least one application program; and a program executing section, checks a possibility that the secret data could be leaked out to the external unit, and stops the execution of the at least one application program when it is determined that the secret data could be leaked out. The check of the possibility that the secret data could be leaked out is based on whether the at least one application program contains a process of communicating with the external unit or a process of writing data in the first storage section and a process of reading the secret data from the second storage section.

1. Field of the Invention
The present invention relates to a program executing method in a service system and a program executing apparatus for the same.
2. Description of the Related Art
Conventionally, a system using a computer and a mobile terminal such as a mobile phone is known, as shown in FIG. 1. In such a system, a program is acquired or downloaded from a service provider through a network and is executed. Referring to FIG. 1, the system is composed of a program executing apparatus 500, a server 200 and a network 50 connecting them.
The program executing apparatus 500 is a mobile terminal in this example. The program executing apparatus 500 is composed of a program storage section 510, a program acquiring section 520, a program executing section 530, a communication section 540, a storage section 550 and a personal data generating section 560. The communication section 540 communicates with the server 200 through the network 50. The program acquiring section 520 acquires a program from the server 200 through the communication section 540. The program storage section 510 stores the program acquired by the program acquiring section 520. The program executing section 530 executes the program stored in the program storage section 510. The storage section 550 stores data. The personal data generating section 560 generates personal data such as the position data of a user using GPS (Global Positioning System).
Here, the program is the data in which the processes to be executed by the program executing apparatus 500 are described. The program executing section 530 interprets the program and executes the processes described therein. The processes to be executed by the program executing section 530 are a communication process with an external unit through the communication section 540, a read process and write process of the data from and into the storage section 550, an input/output process between the program executing apparatus 500 and a user through a user interface, and a reference process of the personal data in the personal data generating section 560.
Next, the operation of the above system will be described. A specific program for executing specific processes is stored in the server 200. An example of a service provided by the specific program is a game, an office work, a map display and so on. The user of the program executing apparatus 500 specifies an identifier of the specific program and requests acquisition of the specific program. The program acquiring section 520 acquires the specified program from the server in response to the request and stores it in the program storage section 510. Subsequently, the user requests the execution of the specific program stored in the program storage section 510. The specified program is interpreted and executed by the program executing section 530.
In this way, the user can receive the service provided by the specific program by acquiring the program stored in the server 200 and executing it. Here, there is a case that the specific program contains a read process of the data stored in the storage section 550 or a reference process of the personal data in the personal data generating section 560 by the program executing section 530, and a communication process through the communication section 540. In this case, however, there is a possibility that optional data in the storage section 550 and the personal data generating section 560 are transmitted through the network 50 to an external unit, such as the server 200 other than the program executing apparatus 500. As a result, the personal data stored in the storage section 550 and the personal data generated by the personal data generating section 560, i.e., the data about privacy and security are leaked to the external unit. In order to avoid such a situation, in the conventional program executing apparatus 500, only one of the communication function and the read function of the data in the storage section 550 and the personal data generating section 560 is given to the program executing apparatus 500. More specifically, the program executing apparatus 530 used has the communication function but does not have the read function of the data from the storage section 550 and the personal data generating section 560, or it has the read function of the data from the storage section 550 and the personal data generating section 560, but does not have the communication function.
It should be noted that in the former case, it is possible that the program executing apparatus 500 reads the personal data from a specific area of the storage section 550. For example, in the mobile terminal, an exclusive use storage section for only the program is provided. Also, the program executing section 530 limits a read process by a program to the storage section 550 and the personal data storage section 560—other than the exclusive use storage section—so that leakage of the personal data such as a telephone directory can be avoided. In this way, the program executing apparatus 500 is realized which can execute an external program while guaranteeing the safety of the personal data.
However, in the conventional program executing apparatus, even the process which never leaks internal data is prohibited as the result of the limitation of the program executing section 530. Specifically, a program cannot be executed in which the data stored in the server 200 and the data stored in the storage section 550 are combined to provide a service to the user. An example of such a program is a calendar display in which personal schedule data of the user, stored in the storage section 550, and weather forecast data for the near future, stored in the server 200, are combined. In this case, it is impossible to execute the above program in the conventional program executing apparatus, in spite of the fact that the personal data of the user is never leaked outside. If the program executing section 530 is provided with the read function of the data from the storage section 550 and the personal data generating section 560 in addition to the communication function, it is not possible to guarantee the avoidance of leakage of the internal data.
In conjunction with the above description, a continuation data server apparatus is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 9-138735). In this conventional example, the continuation data the server apparatus is composed of a plurality of data memory control units which read desired continuation data from a data storage section which stores the continuation data. The plurality of buffer storage sections hold the continuation data which is read out by the data memory control unit. At least one communication control section reads the continuation data which is held by the buffer storage sections and sends to an accommodated channel. The buffer storage section is provided for a combination of the data memory control unit and the communication control section.
Also, a data sharing computer system is disclosed in Japanese Laid Open Patent Application (JP-P2000-276457A). In this conventional example, the data sharing computer system is composed of a first computer system, a second computer system, a shared data storage section, and an access permission/non-permission data storage section. The shared data storage section has a plurality of data storage areas, and divisionally stores the shared data which is accessed by the first computer system and the second computer system from the plurality of data storage areas. The access permission/non-permission data storage section stores access permission/non-permission data for each data storage area of the shared data storage section to indicate whether the area is accessible or not. The first computer system is composed of a first service section, a first data access section connected with the shared data storage section, and a first exclusive control section connected with the access permission/non-permission data storage section. The first service section instructs an access to an optional data storage area to the first data access section and the first exclusive control section. The first exclusive control section acquires the access permission/non-permission data for the instructed data storage area, and determines the permission or non-permission of the access to the instructed data storage area. When it is determined to be accessible, the first exclusive control section changes the access permission/non-permission data corresponding to the instructed data storage area into an access non-permission data. The first data access section accesses the instructed data storage area after the instructed data storage area is determined to be accessible by the first exclusive control section, and the access permission/non-permission data is changed into the access non-permission data. The first exclusive control section changes the access permission/non-permission data for the instructed data storage area into the permission data after the first data access section acceses the instructed data storage area.
The second computer system is composed of a second service section, a second data access section connected with the shared data storage section, and a second exclusive access control section connected with the access permission data storage section. The second service section instructs an access to an optional data storage area to the second data access section and the second exclusive access control section. The second exclusive access control section acquires the access permission/non-permission data corresponding to the instructed data storage area, and determines the permission of the access to the instructed data storage area. When it is determined to be accessible, the second exclusive access control section changes the access permission/non-permission data corresponding to the instructed data storage area into the non-permission data. The second data access section accesses the data storage area determined to be accessible by the second exclusive access control section after the access permission/non-permission data is changed into the non-permission data. The second exclusive access control section changes the access permission/non-permission data corresponding to the instructed data storage area into the permission data after the instructed data storage area is accessed by the second data access section.
Also, a sharing memory access control apparatus is disclosed in Japanese Laid Open Patent Application (JP-P2001-5720A). In this conventional example, the sharing memory access control apparatus is provide to control accesses to a dual port-type memory by each process in the environment in which a plurality of processes sharing the dual port-type memory uses the memory and carries out the processes. The memory contains control data which includes a plurality of bits and whose values are updated in accordance with the cooperation of the plurality of processes. The sharing memory access control apparatus is composed of a detection section for detecting the values of the control data and an updating section for updating the values of the control data. An instructing section controls the detection section to repeat the detecting operation of the values of the control data until the values of the control data are updated to predetermined values by the other processes. When the update of the values to the predetermined values is detected by the detection section, the instructing section instructs a self-process to operate the process. When the operation of the self-process completes, the instructing section instructs the updating section to change the bits of "1" of the control data into "0" and communicates the progress to the other process.
Also, a method of communicating data through a channel with a low reliability is disclosed in Japanese Laid Open Patent Application (JP-P2001-148697A). This conventional example is relates to a method of manufacturing a device used by an operator and communicated with another device which acts on the operator. A maker has a maker key which it is impossible to acquire for a stranger other than the maker and an agent permitted by the maker, the communication is carried out by use of the channel with the low reliability which is not guaranteed from the message change. The device is manufactured to be not necessary to contain a secret about the operator and to contain a secure section as a circuit contained in the transformation impossible boundary. The device is initialized using a specific device identifier by the manufactured device.

Program executing method in service system and program executing apparatus for the same


In the data transmission method of an HSDPA system according to the present invention, a transmitter transmits Data Blocks each composed of one or more data units originated from a same logical channel, and a receiver receives the Data Block through a HS-DSCH and distributes the Data Block to a predetermined reordering buffer. Since each Data Block is composed of the MAC-d PDUs originated from the same logical channel, it is possible to monitor the in-sequence delivery of the data units, resulting in reduction of undesirable queuing delay caused by logical channel multiplexing.

1. Field of the Invention
The present invention relates to a wireless communication system and, more particularly, to a method for reducing the transmission delay of packet data in a mobile radio communication system.
2. Description of the Background Art
A universal mobile telecommunications system (UMTS) is a third generation mobile communication system that has evolved from a standard known as Global System for Mobile communications (GSM). This standard is a European standard which aims to provide an improved mobile communication service based on a GSM core network and wideband code division multiple access (W-CDMA) technology. In December, 1998, the ETSI of Europe, the ARIB/TTC of Japan, the T1 of the United States, and the TTA of Korea formed a Third Generation Partnership Project (3GPP) for the purpose of creating the specification for standardizing the UMTS.
The work towards standardizing the UMTS performed by the 3GPP has resulted in the formation of five technical specification groups (TSG), each of which is directed to forming network elements having independent operations. More specifically, each TSG develops, approves, and manages a standard specification in a related region. Among them, a radio access network (RAN) group (TSG-RAN) develops a specification for the function, items desired, and interface of a UMTS terrestrial radio access network (UTRAN), which is a new RAN for supporting a W-CDMA access technology in the UMTS.
The TSG-RAN group includes a plenary group and four working groups. Working group 1 (WG1) develops a specification for a physical layer (a first layer). Working group 2 (WG2) specifies the functions of a data link layer (a second layer) and a network layer (a third layer). Working group 3 (WG3) defines a specification for an interface among a base station in the UTRAN, a radio network controller (RNC), and a core network. Finally, Working group 4 (WG4) discusses requirements desired for evaluation of radio link performance and items desired for radio resource management.
FIG. 1 shows a structure of a 3GPP UTRAN. This UTRAN 110 includes one or more radio network sub-systems (RNS) 120 and 130. Each RNS 120 and 130 includes a RNC 121 and 131 and one or more Nodes B 122 and 123 and 132 and 133 (e.g., a base station) managed by the RNCs. RNCs 121 and 131 are connected to a mobile switching center (MSC) 141 which performs circuit switched communications with the GSM network. The RNCs are also connected to a serving general packet radio service support node (SGSN) 142 which performs packet switched communications with a general packet radio service (GPRS) network.
Nodes B are managed by the RNCs, receive information sent by the physical layer of a terminal 150 (e.g., mobile station, user equipment and/or subscriber unit) through an uplink, and transmit data to a terminal 150 through a downlink. Nodes B, thus, operate as access points of the UTRAN for terminal 150.
The RNCs perform functions which include assigning and managing radio resources. An RNC that directly manages a Node B is referred to as a control RNC (CRNC). The CRNC manages common radio resources. A serving RNC (SRNC), on the other hand, manages dedicated radio resources assigned to the respective terminals. The CRNC can be the same as the SRNC. However, when the terminal deviates from the region of the SRNC and moves to the region of another RNC, the CRNC can be different from the SRNC. Because the physical positions of various elements in the UMTS network can vary, an interface for connecting the elements is necessary. Nodes B and the RNCs are connected to each other by an lub interface. Two RNCs are connected to each other by an lur interface. An interface between the RNC and a core network is referred to as lu.
FIG. 2 shows a structure of a radio access interface protocol between a terminal which operates based on a 3GPP RAN specification and a UTRAN. The radio access interface protocol is horizontally formed of a physical layer (PHY), a data link layer, and a network layer and is vertically divided into a control plane for transmitting a control information and a user plane for transmitting data information. The user plane is a region to which traffic information of a user such as voice or an IP packet is transmitted. The control plane is a region to which control information such as an interface of a network or maintenance and management of a call is transmitted.
In FIG. 2, protocol layers can be divided into a first layer (L1), a second layer (L2), and a third layer (L3) based on three lower layers of an open system interconnection (OSI) standard model well known in a communication system.
The first layer (L1) operates as a physical layer (PHY) for a radio interface and is connected to an upper medium access control (MAC) layer through one or more transport channels. The physical layer transmits data delivered to the physical layer (PHY) through a transport channel to a receiver using various coding and modulating methods suitable for radio circumstances. The transport channel between the physical layer (PHY) and the MAC layer is divided into a dedicated transport channel and a common transport channel based on whether it is exclusively used by a single terminal or shared by several terminals.
The second layer L2 operates as a data link layer and lets various terminals share the radio resources of a W-CDMA network. The second layer L2 is divided into the MAC layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a broadcast/multicast control (BMC) layer.
The MAC layer delivers data through an appropriate mapping relationship between a logical channel and a transport channel. The logical channels connect an upper layer to the MAC layer. Various logical channels are provided according to the kind of transmitted information. In general, when information of the control plane is transmitted, a control channel is used. When information of the user plane is transmitted, a traffic channel is used. The MAC layer is divided two sub-layers according to performed functions. The two sub-layers are a MAC-d sub-layer that is positioned in the SRNC and manages the dedicated transport channel and a MAC-c/sh sub-layer that is positioned in the CRNC and manages the common transport channel.
The RLC layer forms an appropriate RLC protocol data unit (PDU) suitable for transmission by the segmentation and concatenation functions of an RLC service data unit (SDU) received from an upper layer. The RLC layer also performs an automatic repeat request (ARQ) function by which an RLC PDU lost during transmission is re-transmitted. The RLC layer operates in three modes, a transparent mode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM). The mode selected depends upon the method used to process the RLC SDU received from the upper layer. An RLC buffer stores the RLC SDUs or the RLC PDUs received from the upper layer exists in the RLC layer.
The packet data convergence protocol (PDCP) layer is an upper layer of the RLC layer which allows data items to be transmitted through a network protocol such as the IPv4 or the IPv6. A header compression technique for compressing and transmitting the header information in a packet can be used for effective transmission of the IP packet.
The broadcast/multicast control (BMC) layer allows a message to be transmitted from a cell broadcast center (CBC) through the radio interface. The main function of the BMC layer is scheduling and transmitting a cell broadcast message to a terminal. In general, data is transmitted through the RLC layer operating in the unacknowledged mode.
The PDCP layer and the BMC layer are connected to the SGSN because a packet switching method is used, and are located only in the user plane because they transmit only user data. Unlike the PDCP layer and the BMC layer, the RLC layer can be included in the user plane and the control plane according to a layer connected to the upper layer. When the RLC layer belongs to the control plane, data is received from a radio resource control (RRC) layer. In the other cases, the RLC layer belongs to the user plane. In general, the transmission service of user data provided from the user plane to the upper layer by the second layer (L2) is referred to as a radio bearer (RB). The transmission service of control information provided from the control plane to the upper layer by the second layer (L2) is referred to as a signaling radio bearer (SRB). As shown in FIG. 2, a plurality of entities can exist in the RLC and PDCP layers. This is because a terminal has a plurality of RBs, and one or two RLC entities and only one PDCP entity are generally used for one RB. The entities of the RLC layer and the PDCP layer can perform an independent function in each layer.
The RRC layer positioned in the lowest portion of the third layer (L3) is defined only in the control plane and controls the logical channels, the transport channels, and the physical channels in relation to the setup, the reconfiguration, and the release of the RBs. At this time, setting up the RB means processes of stipulating the characteristics of a protocol layer and a channel, which are required for providing a specific service, and setting the respective detailed parameters and operation methods. It is possible to transmit control messages received from the upper layer through a RRC message.
The aforementioned W-CDMA system attempts to achieve a transmission speed of 2 Mbps indoors and in a pico-cell circumstance, and a transmission speed of 384 kbps in a general radio condition. However, as the wireless Internet becomes more widespread and the number of subscribers increases, more diverse services will be provided. In order to support these services, it is expected that higher transmission speeds will be necessary. In the current 3GPP consortium, research is being performed to provide high transmission speeds by developing the W-CDMA network. One representative system is known as the high-speed downlink packet access (HSDPA) system.
The HSDPA system is based on WCDMA. It supports a maximum speed of 10 Mbps to the downlink and is expected to provide shorter delay time and an improved capacity than existing systems. The following technologies have been applied to the HSDPA system in order to provide higher transmission speed and enlarged capacity: link adaptation (LA), hybrid automatic repeat request (HARQ), fast cell selection (FCS), and multiple input, multiple output (MIMO) antenna.
The LA uses a modulation and coding scheme (MCS) suitable for the condition of a channel. When the channel condition is good, high degree modulation such as 16QAM or 64QAM is used. When the channel condition is bad, low degree modulation such as QPSK is used.
In general, low degree modulation methods support a lesser amount of transmission traffic than high degree modulation methods. However, in low degree modulation methods, a transmission success ratio is high when a channel condition is not desirable and therefore, it is advantageous to use this form of modulation when the influences of fading or interference is large. On the other hand, frequency efficiency is better in high degree modulation methods than in low degree modulation methods. In the high degree modulation methods, it is possible, for example, to achieve a transmission speed of 10 Mbps using the 5 MHz bandwidth of W-CDMA. However, high degree modulation methods are very sensitive to noise and interference. Therefore, when a user terminal is located close to a Node B, it is possible to improve transmission efficiency using 16QAM or 64QAM. And, when the terminal is located on the boundary of the cell or when the influence of fading is large, low modulation method such as QPSK is useful.
The HARQ method is a re-transmission method which differs from existing re-transmission methods used in the RLC layer. The HARQ method is used in connection with the physical layer, and a higher decoding success ratio is guaranteed by combining re-transmitted data with previously received data. That is, a packet that is not successfully transmitted is not discarded but stored. The stored packet is combined with a re-transmitted packet in a step before decoding and is decoded. Therefore, when the HARQ method is used together with the LA, it is possible to significantly increase the transmission efficiency of the packet.
The FCS method is similar to a related art soft handover. That is, the terminal can receive data from various cells. However, in consideration of the channel condition of each cell, the terminal receives data from a single cell which has the best channel condition. The related art soft handover methods increase the transmission success ratio using diversity, and more specifically, by receiving data from various cells. However, in the FCS method, data is received from a specific cell in order to reduce interference between cells.
Regarding the MIMO antenna system, the transmission speed of data is increased using various independent radio waves propagated in the dispersive channel condition. The MIMO antenna system usually consists of several transmission antennas and several reception antennas, so that diversity gain is obtained by reducing correlation between radio waves received by each antenna.
The HSDPA system, thus, to adopt a new technology based on a WCDMA network. However, in order to graft new technologies, modification is unavoidable. As a representative example, the function of Node B is improved. That is, though most control functions are located in the RNC in a WCDMA network, new technologies for the HSDPA system are managed by the Node B in order to achieve faster adjustment to the channel conditions and to reduce a delay time in the RNC. The enhanced function of the Node B, however, is not meant to replace the functions of the RNC but rather is intended to supplement these functions for high speed data transmission, from a point of view of the RNC.
Thus, in an HDSPA system, the Nodes B are modified to perform some of the MAC functions unlike in the WCDMA system. A modified layer which performs some of the MAC function is referred to as a MAC-hs sub-layer.
The MAC-hs sub-layer is positioned above the physical layer and can perform packet scheduling and LA functions. The MAC-hs sub-layer also manages a new transport channel known as HS-DSCH (High Speed-Downlink Shared Channel) which is used for HSDPA data transmission. The HS-DSCH channel is used when data is exchanged between the MAC-hs sub-layer and the physical layer.
FIG. 3 shows a radio interface protocol structure for supporting the HSDPA system. As shown, the MAC layer is divided into a MAC-d sub-layer, a MAC-c/sh sub-layer, and a MAC-hs sub-layer. The MAC-hs sub-layer is positioned above the physical layer (PHY) of a Node B. The MAC-c/sh and MAC-d sub-layers are located in the CRNC and the SRNC. A new transmission protocol referred to the HS-DSCH frame protocol (FP) is used between the RNC and the Node B or among the RNCs for the delivery of HSDPA data.
The MAC-c/sh sub-layer, the MAC-d sub-layer, and the RLC layer positioned above the MAC-hs sub-layer perform the same functions as the current system. Therefore, a slight modification of the current RNC can fully support the HSDPA system.
FIG. 4 shows the structure of a MAC layer used in the HSDPA system. The MAC layer is divided into a MAC-d sub-layer 161, a MAC-c/sh sub-layer 162, and a MAC-hs sub-layer 163. The MAC-d sub layer in the SRNC manages dedicated transport channels for a specific terminal. The MAC-c/sh sub-layer in the CRNC manages the common transport channels. The MAC-hs sub-layer in the Node B manages the HS-DSCH. In this arrangement, the functions performed by the MAC-c/sh sub-layer 162 in the HSDPA system are reduced. That is, the MAC-c/sh sub-layer assigns common resources shared by various terminals in the conventional system and processes the common resources. However, in the HSDPA system, the MAC-c/sh sub-layer simply performs a flow control function of the data delivery between the MAC-d sub-layer 161 and the MAC-hs sub-layer 163.
Referring to FIG. 4, it will be described how data received from the RLC layer is processed and delivered to the HS-DSCH in the MAC layer. First, the path of the RLC PDU delivered from the RLC layer through the dedicated logical channel, (i.e. a dedicated traffic channel (DTCH) or a dedicated control channel (DCCH)), is determined by a channel switching function in the MAC-d layer. When an RLC PDU is delivered to the dedicated channel (DCH), a related header is attached to the RLC PDU in the MAC-d sub-layer 161 and the RLC PDU is delivered to the physical layer through the DCH. When the HS-DSCH channel of the HSDPA system is used, the RLC PDU is delivered to the MAC-c/s h sub-layer 162 by a channel switching function. When a plurality of logical channels use one transport channel, the RLC PDU passes through a transport channel multiplexing block. The identification information (control/traffic (C/T) field) of the logical channel, to which each RLC PDU belongs, is added during this process. Also, each logical channel has a priority. Data of a logical channel has the same priority.
The MAC-d sub-layer 161 transmits the priority of a MAC-d PDU when the MAC-d PDU is transmitted. The MAC-c/sh sub-layer 162 that received the MAC-d PDU simply passes the data received from the MAC-d sub-layer 161 to the MAC-hs sub-layer 163. The MAC-d PDU delivered to the MAC-hs sub-layer 163 is stored in the transmission buffer in the scheduling block. One transmission buffer exists per each priority level. Each MAC-hs SDU (MAC-d PDU) is sequentially stored in the transmission buffer corresponding to its priority.
An appropriate data block size is selected by the scheduling function depending on the channel condition. Accordingly, a data block is formed by one or more MAC-hs SDUs.
A priority class identifier and a transmission sequence number are added to each data block and each data block is delivered to the HARQ block.
A maximum 8 HARQ processes exist in the HARQ block. The data block received from the scheduling block is delivered to an appropriate HARQ process. Each HARQ process operates in a stop and wait (SAW) ARQ. In this method, the next data block is not transmitted until a current data block is successfully transmitted. As mentioned above, because only one data block is transmitted in a TTI, only one HARQ process is activated in one TTI.
Another HARQ processes waits until its turn. Each HARQ process has a HARQ process identifier. A corresponding HARQ process identifier is previously known to the terminal through a downlink control signal, so that a specific data block passes through the same HARQ process in the transmitter (the UTRAN) and the receiver (the terminal). The HARQ process that transmitted the data block also stores the data block to provision the future re-transmission. The HARQ process, re-transmits the data block when NonACKnowledge (NACK) is received from the terminal.
When ACK is received from the terminal, the HARQ process deletes the corresponding data block and prepares the transmission of a new data block. When the data block is transmitted, a transport format and resource combination (TFRC) block selects an appropriate TFC for the HS-DSCH.
FIG. 5 shows a structure of the MAC layer of the terminal used in the HSDPA system. This MAC layer is divided into a MAC-d sub-layer 173, a MAC-c/sh sub-layer 172, and a MAC-hs sub-layer 171. Unlike the UTRAN, the above three layers are located in the same place. The MAC-d sub-layer and the MAC-c/sh sub-layer in the terminal are almost same as those in the UTRAN, but the MAC-hs sub-layer 171 is slightly different because the MAC-hs sub-layer in the UTRAN performs only transmission and the MAC-hs sub-layer in the terminal performs only reception.
The manner in which the MAC layer receives the data from the physical layer and delivers it to the RLC layer will now be described. The data block delivered to the MAC-hs sub-layer 171 through the HS-DSCH is first stored in one of the HARQ processes in the HARQ block. In which process the data block is stored can be known from the HARQ process identifier included in the downlink control signal.
The HARQ process, in which the data block is stored, transmits the NACK information to the UTRAN when there are errors in the data block and requests the re-transmission of the data block. When no errors exist, the HARQ process delivers the data block to a reordering buffer and transmits the ACK information to the UTRAN. A reordering buffer has a priority like the transmission buffer in the UTRAN. The HARQ process delivers the data block to the corresponding reordering buffer with the aid of a priority class identifier included in the data block. A significant characteristic of the reordering buffer is that it supports in-sequence delivery of data.
Data blocks are sequentially delivered to an upper layer based on a transmission sequence number (TSN). More specifically, when a data block is received while one or more previous data blocks are missing, the data block is stored in the reordering buffer and is not delivered to the upper layer. Rather, the stored data block is delivered to the upper layer only when all previous data blocks are received and delivered to the upper layer. Because several HARQ processes operate, a reordering buffer usually receives data blocks out of sequence. Therefore, an in-sequence delivery function is used for the reordering buffer so that the data blocks can be delivered to the upper layer sequentially.
One difference between the reordering buffer of the terminal and the transmission buffer of the UTRAN is that the reordering buffer stores data in units of data block which is composed of one or more MAC-hs SDUs, while the transmission buffer stores data in units of MAC-hs SDU (=MAC-d PDU). Because the MAC-d sub-layer 173 processes data in units of MAC-d PDUs, when the reordering buffer of the terminal MAC-hs sub-layer 171 delivers the data block to the MAC-d sub-layer 173, the reordering buffer must first disassemble the data block into the MAC-d PDUs and then deliver them to the MAC-d sub-layer. The MAC-c/sh sub-layer 172 passes the MAC-d PDUs received from the MAC-hs sub-layer 171 to the MAC-d sub-layer. The MAC-d sub-layer 173 that received the MAC-d PDU checks the logical channel identifier (C/T field) included in each MAC-d PDU in the transport channel multiplexing block and delivers the MAC-d PDUs to the RLC through the corresponding logical channel.
FIG. 6 shows processes for transmitting and receiving a data block in an HSDPA system. The MAC-d PDUs are actually stored in a transmission buffer 180. However, for the sake of convenience, it is shown as a data block (=one or more MAC-d PDUs). The sizes of the respective data blocks can vary. However, the sizes are shown to be the same because the data blocks for illustrative purposes. Also, it is assumed that eight HARQ processes 181 through 188 exist.
The process includes transmitting data blocks to the receiver for data blocks having transmission sequence numbers from TSN=13 to TSN=22 in the transmission buffer. A data block with a lower TSN is served first to an empty HARQ process. For example, as shown, the data block TSN=13 is delivered to HARQ process #1 181, and data block TSN=14 is delivered to HARQ process #8. From this explanation, it is clear that the TSN is not related to the HARQ process number.
When the HARQ process receives an arbitrary data block, the HARQ process transmits the data block to the receiver in a specific TTI and stores the data block for re-transmission that might be performed later. Only one data block can be transmitted in a certain TTI. Accordingly, only one HARQ process is activated in a single TTI. The HARQ process that transmitted the data block informs the receiver of its process number through a downlink control signal which is transmitted through a different channel than that of the data block.
The reason why the HARQ process of the transmitter coincides with the HARQ process of the receiver is that a stop-and-wait ARQ method is used by each HARQ process pair. That is, HARQ process #1 181 that transmitted data block TSN=13 does not transmit another data block until the data block is successfully transmitted. Because a receiver HARQ process #1 191 can know that data is transmitted thereto for a corresponding TTI through the downlink control signal, the receiver HARQ process #1 transmits the NACK information to the transmitter through an uplink control signal when the data block is not successfully received within a defined transmission time interval (TTI). On the other hand, when a data block is successfully received, the receiver HARQ process #1 transmits the ACK information to the transmitter, and at the same time delivers the corresponding data block to the reordering buffer according to the priority.
The reordering buffer exists per priority level. The HARQ process checks the priority included in the header information of the data block and delivers the data block to the reordering buffer according to the priority. The data block delivered to the reordering buffer is then delivered to the upper layer when all of the previous data blocks are delivered to the upper layer. However, when one or more previous data blocks are not delivered to the upper layer, the data block is stored in the reordering buffer 190. That is, the reordering buffer must support in-sequence delivery of data blocks to the upper layer. A data block that is not delivered to the upper layer is stored in the reordering buffer.
To illustrate the foregoing, FIG. 6 shows that when data block TSN=14 is received but data block TSN=13 is not received, data block TSN=14 is stored in the reordering buffer until data block TSN=13 is received. When data block TSN=13 is received, both data blocks are delivered to the upper layer in the order of TSN=13 and TSN=14. When the data blocks are delivered to the upper layer, they are disassembled in units of MAC-d PDUs and are delivered as described above.
FIG. 7 is a data block (MAC-hs PDU) format adopted in the HSDPA system. As shown in FIG. 7, the data block consists of a MAC-hs header including control information and a MAC-hs payload carrying the upper layer PDU.
The MAC-hs header includes a Queue ID field and a TSN field, and the MAC-hs payload includes a plurality of MAC-hs SDUs (MAC-d PDUs). Each MAC-d PDU includes the C/T field and the MAC-d SDU (RLC PDU). The C/T field is included in the MAC-d PDU header if multiplexing on MAC is applied, and it provides identification of the logical channel when multiple logical channels are carried on the same transport channel. Four bits are currently allocated for C/T field in order to identify up to 15 different logical channels (1111 is reserved). Since a radio bearer is usually mapped to one logical channel, the C/T field can be further used for identification of radio bearer.
FIG. 8 is a flowchart illustrating how to deliver the received data blocks to re-ordering buffer in UE side MAC-hs sublayer.
As shown in FIG. 8, the UE side MAC-hs establishes the reordering buffer according to priority (S801), and checks if a Data Block is received from HARQ entity (S802). If the Data Block is received from HARQ entity, the MAC-hs checks the priority field (S8O3) and forwards the Data Block to the reordering buffer based on priority (S804). Then, the MAC-hs checks the sequence number of the Data Block, i.e. TSN of the Data Block, (S8O5), and determines whether the Data Block can be delivered or not (S8O6). If the Data Block is determined that it can be delivered, the MAC-hs disassembles the Data Block into data units (S807), and checks the logical channel identity of each data units by the C/T field (S8O8). Each of the disassembled data units is then delivered to the corresponding logical channel, respectively (S8O9).
In step S8O6, if the Data Block is determined that it can not be delivered due to one or more missing Data Blocks preceding it, the MAC-hs stores the Data Block in the reordering buffer according to its sequence number instead of delivering it (S810). After the Data Block is processed in the above manner, the UE side MAC-hs determines whether or not the HS-DSCH connection is released (S811). If the HS-DSCH connection is not released, the algorithm goes to the step S802.
FIG. 9 is an exemplary view for illustrating how data blocks consisting of MAC-d PDUs from different logical channels are transmitted in the HSDPA system.
In FIG. 9, 4 data blocks are transmitted from the UTRAN side MAC-hs. For example, Data Block #10 is composed of 3 MAC-d PDUs where 1 MAC-d PDU is originated from a logical channel #1 and 2 MAC-d PDUs originated from a logical channel #2. The figure illustrates the case when Data Block #10, #12, and #13 are successfully received by the UE side MAC-hs while Data block #11 is lost during transmission. Since Data Block #10 has been successfully received, the reordering buffer forwards the Data Block #10 to the upper layer immediately. However, since Data Block #11 is not received, the correctly received Data Block #12 and #13 can not be delivered to the upper layer but just stored in the reordering buffer until Data Block #11 is received or until some stall avoidance mechanism is terminated.
From the viewpoint of logical channel #2, the received MAC-d PDUs are seen as consecutive, since there are no missing MAC-d PDUs between the two adjacent MAC-d PDUs. In other words, since the Data Block #11 does not contain any PDUs from logical channel #2, whether Data Block #11 is received or not does not affect the in-sequence delivery of logical channel #2. Accordingly, if the reordering buffer knows the in-sequence delivery of MAC-d PDUs of a specific logical channel, the MAC-d PDUs can be immediately delivered to the upper layer without being delayed in the reordering buffer.
As described above, the multiplexing of logical channels has a drawback in that delivery of MAC-d PDUs of one logical channel may be unnecessarily delayed due to a missing MAC-d PDU of other logical channel. Moreover, the delayed MAC-d PDUs sometimes become useless because of the discards in the RLC layer.


Disclosed herein are an electrostatic discharging structure including single-wall carbon nano tubes disposed between electrodes at a predetermined interval to precisely control discharge starting voltage generating a discharge phenomenon between electrodes, and a method of manufacturing an electrostatic discharging structure.

1. Technical Field
The present invention relates to an electrostatic discharging structure and a method of manufacturing the same.
2. Description of the Related Art
Recently, in accordance with the tendency of miniaturization, slimness and high function of electronic devices, demands for performance improvement, miniaturization and slimness of electronic components applied to electronic devices have increased.
Further, as portability of electronic devices becomes more important, the electronic devices need to be operated at high speed under low-voltage and low-current environment, and therefore the withstand voltage of the electronic components needs to be reduced accordingly.
However, various types of electronic devices to which the electronic components are applied may be frequently applied with overvoltage or overcurrent, that is, not within a tolerable range due to instability, static electricity, and the like, of an input power supply.
When overvoltage or overcurrent is applied to electronic devices, the deterioration phenomenon of electronic devices or the malfunction of electronic components and electronic device including the same may be induced.
Therefore, attempts to develop technologies for discharging static electricity through a safe path so as to prevent static electricity from being introduced into electronic devices or electronic components or portions sensitive to static electricity from being damaged even though static electricity is introduced into electronic devices have been continuously conducted.
Meanwhile, Patent Documents 1, 2, and 3, and the like, disclose an electrostatic protection device, and the like.
However, the existing electrostatic protection technologies including Patents 1 to 3, and the like, provide a structure of reducing discharge starting voltage but have a limitation in precisely controlling a range of the discharge starting voltage.

Electrostatic discharging structure and method of manufacturing the same