A method and apparatus for diagnosing causes of a malfunction of an electronic whiteboard that includes a white-board surface, the method comprising the steps of linking a remote computer that includes a remote display to the electronic whiteboard from a remote location, interacting with the whiteboard surface to generate X and Y coordinates associated with surface activity, transmitting at least one of the X and Y coordinates associated with the surface activity to the remote computer, displaying at least a subset of the at least one of X and Y coordinates via the remote display and examining the at least a subset of the at least one of X and Y coordinates via the remote display to ascertain the cause of a board malfunction.

The present invention relates to electronic whiteboards and more specifically to remote diagnostic systems for electronic whiteboards.
Various types of electronic whiteboards have been developed to help people share information. To this end, most electronic whiteboards include a large flat surface on which information is applied for viewing by people within a conference or other type of space, some type of a sensor system for sensing interactive activities with the whiteboard surface that are intended to alter the information presented on the surface, some type of whiteboard driver for controlling the information that is present on the whiteboard surface and a computer (e.g., a laptop, PC, etc.) to run whiteboard and other software applications.
In some cases a whiteboard system will include a large liquid crystal display (LCD) or a plasma display for presenting information and the driver will be a display driver. Here, the sensor systems typically include a laser type system that senses the locations of pen tips, the location of a finger tip, etc., adjacent the front surface of the display to determine when image altering activities are occurring. In other cases the whiteboard system will include a projector that projects images on the whiteboard surface and the whiteboard surface may be touch sensitive. Exemplary touch sensitive whiteboards may include first and second layers that form the whiteboard surface where pressing of a pen tip against the first layer causes the rear surface thereof to contact the front surface of the second layer and where the contact location between the first and second layers can be sensed. In still other cases the whiteboard may be equipped with ultrasonic sensors and a writing device (e.g., a pen) to be used therewith may generate a clicking noise that is sensed by the sensors and that can be used in a triangulation process to identify pen tip location. In any of the above cases, as a change is made to alter a whiteboard image (e.g., a pen tip is moved diagonally across the whiteboard surface), the activity is sensed and used to alter the surface image.
In the case of a system that includes a touch sensitive whiteboard surface and a projected image, a precise calibration of the projected image to the whiteboard surface is required for the system to reproduce image changes that accurately reflect image altering activities performed by a person using the whiteboard. One solution for aligning a projected image with a whiteboard sensing system is to facilitate a calibration commissioning procedure wherein a known image is projected onto the whiteboard that includes reference points. A system user contacts each of the reference points with a stylus or the like to earmark the locations. Thereafter the system computer stores the locations of the reference points and uses those points to calibrate other locations on the whiteboard surface. While this solution works well when performed properly, when this solution is not performed properly or is performed in a sloppy fashion (e.g., the points selected by the user are not precisely aligned with the projected reference points), alignment is inaccurate and activities on the whiteboard surface intended to alter whiteboard images are imprecisely replicated by the whiteboard.
After a whiteboard has been calibrated or has been calibrated and the projection from a projector is aligned with the whiteboard surface during a commissioning procedure, during operation of the whiteboard, the whiteboard can malfunction in several different ways. For instance, several different occurrences can degrade or substantially hinder pen/stylus tip tracking including lose or corruption of calibration data (e.g., due tot a power surge), sensor malfunctions, a short in between layered whiteboard sensors (e.g., due to debris lodged between layers), whiteboard power fluctuations, etc.
As another instance, several different whiteboard components can malfunction independent of other whiteboard components. For example, whiteboard LEDs that indicate specific activities can burn out or otherwise be rendered unable to be illuminated. As another example, a whiteboard cooling fan can malfunction. Other exemplary components that can malfunction include sound generators (e.g., speakers), a whiteboard processor, etc.
As still one other instance, a whiteboard can malfunction when the laptop or PC used to control the whiteboard has application programs loaded thereon that are incompatible with the whiteboard application programs. Thus, for instance, where a laptop has thirty different applications programs loaded in addition to the whiteboard application program, it may be that two of the application programs in addition to the whiteboard application program are not compatible with the whiteboard program so that the whiteboard program malfunctions in some respects during whiteboard activities.
In many cases symptoms of whiteboard malfunction may result from any of several different causes and in these cases it is often difficult to determine what a symptom is indicating. For instance, where a whiteboard does not accurately track the tip of a stylus, is the inaccurate tracking symptom caused by loss or degradation of calibration data, a malfunctioning sensor, a malfunctioning board processor, a power malfunction, etc. As another instance, where an LED does not illuminate when anticipated, is the dark LED an indication that the LED is not working, that a sensor linked to the LED has malfunctioned or that the operating characteristic associated with the dark LED has not occurred. As still one other instance, when a fan does not rotate when expected, is the still fan an indication that the fan is not working, that a temperature sensor that controls the fan is not working or that the whiteboard temperature is simply to low for the fan to rotate.
Typically when a whiteboard malfunctions, a technician is dispatched to the location of the board on a service call. Once the technician arrives at the board location, the technician observes the malfunction symptoms and assesses likely causes of the malfunction. Next the technician performs various tests to determine the cause(s) of the malfunction and then the technician repairs or reprograms (e.g., performs a recalibration process to regenerate calibration data for the board) the board to eliminate the malfunction.
While dispatching a technician works well to correct malfunctions, this solution has several shortcomings. First, technicians are often highly trained people and therefore their time is very expensive. Dedicated technician trips to board locations are expensive and therefore should be avoided whenever possible.
Second, qualified technicians are not always immediately available for dispatch to malfunctioning boards and therefore there is often a delay between the time a request for technical support is lodged and the time at which a technician arrives at a board location to diagnose the cause of a malfunction. This board down time is, at a minimum, a nuisance and in many cases can affects productivity of people that use the board.
Third, in some cases malfunctions are relatively minor and do not affect the overall operation of a whiteboard for its primary purpose. For instance, where an LED malfunctions, other whiteboard components may still operate effectively so that the board can be used for its primary and intended purpose despite the dark LED. If a board user could ascertain that the LED has burnt out and that the dark LED is not indicating some more serious system problem, the user may forego repair/replacement of the LED to avoid the technician cost or may simply put off LED replacement until a more urgent maintenance issue occurs thereby reducing (i.e., one dispatch instead of two) and delaying costs. In the alternative, a board user may be able to easily repair a malfunctioning component (e.g., a burnt out LED) thereby eliminating the need for technician dispatch altogether.
In the computer industry remote diagnostics systems have been developed that allow an IT technician to patch into a local PC or laptop computer to observe a user's desk top activities. Here, in at least some cases, the IT technician is provided a copy of the local computer's desktop in a window and, in addition to being able to observe the desktop image, can run desktop applications in the same way that the local computer can be used to run the applications. In these cases, when the remote computer runs the applications on the local computer, the remote image mirrors the local image. While this solution works well in the case of PCs and laptops where software programs are to be examined for faulty operation, this solution does not work well in the case of a whiteboard where, when the board malfunctions, mirroring of the board image alone would be no more instructive as to the cause of the malfunction than if the technician were at the board location observing the board itself. Thus, for instance, where the board fails to accurately track pen tip movement there across, mirroring of the board image would simply generate an image from which the tracking inaccuracy alone could not be identified. As another instance, where an LED remains dark when it should have been illuminated, known remote diagnostic systems could not be used to ascertain or narrow down the cause (e.g., burnt out LED, malfunctioning sensor, etc.) of the dark LED.

Remote diagnostics for electronic whiteboard


A dual chamber dispenser is formed of a first chamber and a second chamber connected together by a one-way valve with the first chamber holding a flowable first component to be mixed at a time of use with a second component in the second chamber. The one-way valve permits flow from the first chamber into the second chamber but prevents any backflow from the second chamber to the first chamber. A metered dose outlet chamber is connected to the second chamber by way of another one-way valve, so that the mixed components can be directed into the outlet chamber but prevented from backflow into the second chamber. A dispensing head is connected to the outlet chamber for collapsing the outlet chamber and dispensing selected amounts of the mixed components. With the components in the first and second chambers kept in a separated condition the dispenser has a long shelf life though the mixed components have only a relatively short period of use after the mixing has been effected.

The present invention is directed to a dispenser containing dual chambers. One of the chambers contains a substance to be mixed with another substance such as a diluent, in the other chamber. The chambers are maintained so that there is no flow between them during a storage period. When the dispenser is to be used, substances are mixed by introducing the substances from one chamber into the other.
In the past dual chamber dispensers have been used for solutions or mixtures having a relatively short use life. The two components of such a solution must be kept separate during shelf storage to prevent the deterioration of the solution prior to its use.
When the solution being used is a pharmaceutical or drug solution, it is important that the solution, when prepared for use, is maintained free of contamination. If contamination in the form of moisture, dust, gases in the ambient atmosphere and the like, enter the solution it is possible that the solution will be rendered unfit for use.

ReSeal International Limited Partnership


The present application discloses a light-emitting apparatus having a light-emitting device and a wavelength conversion layer. The light-emitting device has a first top surface and a first side surface, and the wavelength conversion layer has a second top surface and a second side surface and covers the first top surface. A ratio of a distance between the first top surface to the second top surface and a distance between the first side surface and the second side surface is between 1.1˜1.3.

Technical Field
The present disclosure relates to a light-emitting apparatus and in particular to a light-emitting apparatus having a semiconductor light-emitting element and an optical element.
Description of the Related Art
A light-emitting device having light-emitting diode (LED) is gradually taking the place of traditional incandescent light for energy saving, environmental protection, long operation life, compact, and so on.
Various kinds of optical elements, such as lens, reflector, and wavelength converter, can be used to change the optical properties of the light-emitting device. The lens can be used to collect or redistribute light from LEDs. The reflector can redirect light from LEDs to a desired direction. Moreover, the wavelength converter, such as phosphor, dye, or quantum dot, can convert color light from LEDs to another one.


A wireless communication network can reliably deliver high priority broadcast information from base stations to mobile terminals located deep in building and those located in scarcely populated areas that are remote from the base stations. Each of the base stations of the wireless communication network comprises a broadcast information input unit for receiving high priority broadcast information and a transmission power changing unit for changing the transmission power of the downlink common channel when high priority broadcast information is input to it. As broadcast information is input, the transmission power changing unit changes the transmission power of the downlink common channel so as to boost the effective radiation power used by the downlink common channel of the base station at places in the coverage of the base station that are subjected to a propagation loss. The effective radiation power to the mobile terminals located at places in the coverage of the base station that are subjected to propagation loss is boosted to raise the reception level of the mobile terminals located at such places.

1. Field of the Invention
This invention relates to a wireless communication network in a cellular system formed by a plurality of base stations, which broadcasts information using downlink common channels, transmits information using downlink dedicated channels and receives information using uplink dedicated channels. More particularly, the invention relates to a wireless communication network for broadcasting high priority information using downlink common channels.
2. Description of the Related Art
A prior technique relevant to transmission of high priority information in the wireless communication network has been disclosed by JP-A-10-41875, which describes a communication system and a portable telephone terminal having an function of automatic emergency communication. This terminal changes its transmission method when used for emergency communication so as to transmit high priority information using uplink channels.
Another prior technique has been disclosed by JP-A-10-13336, which describes a public business digital mobile communication system. This system can broadcast high priority information without interrupting individual communications of mobile stations by using idle communication channels or compulsory communication channels in order to transmit and broadcast emergency information, or high priority information.
Of the above-described two techniques, the former is directed to change the transmission method via uplinks, whereas the latter is directed to broadcast by using idle communication channels or compulsory communication channels.
As shown in FIG. 22, each of the base stations of known wireless communication networks having a broadcasting function comprises an uplink dedicated channel reception unit 1, a downlink dedicated channel reception unit 2 and a downlink common channel transmission unit 3.
Normally, a wireless communication system is designed in such a way that the cell radius of an uplink and that of a downlink are substantially equal to each other and base stations are provided for the system in order to realize bidirectional communication via the uplink and the downlink.
Particularly, in W-CDMA (wide band-code division multiple access) type wireless communication systems, the cell radius, or the coverage area, and the wireless communication system capacity qualitatively show a relationship of tradeoff. For this reason, the wireless communication system is designed and regulated so as to make the wireless communication system capacity as large as possible for both the uplinks and the downlinks in order to realize the coverage area that is presumably necessary and sufficient.
Additionally, wireless communication systems have been made to operate as communication systems and, at the same time, as broadcasting systems as in the case of MBMS (multimedia broadcast & multicast systems) in recent years. The functional feature of broadcasting system is realized by using downlinks as common channels for broadcasting information. No problem arises to wireless communication systems that are designed and regulated to operate as broadcasting systems for broadcasting information to the coverage so long as the information to be broadcast has an ordinary level of priority.
However, as the first problem of the prior art, it is not possible to convey the broadcast information quickly and reliably to mobile terminals out of the designed coverage of such a wireless communication system if there occurs a situation where high priority information needs to be broadcast because the system is primarily designed as wireless communication system. Particularly, a place deep in a large building that gives rise to a large propagation loss can often be out of the coverage of the uplink because of the upper limit of the transmission power of the mobile terminal and hence it is also out of the coverage of the downlink. Then, there arises a problem that no broadcast information is conveyed to mobile terminals at places located deep in buildings. Additionally, many scarcely populated areas are designed to be out of the coverage of wireless communication systems because of the profitability of the wireless communication system in addition to a large propagation loss of such areas. Thus, there also arises a problem that no broadcast information is conveyed to mobile terminals of scarcely populated areas.
Conceivable circumstances where high priority broadcast information is transmitted include those where the meteorological agency requests wireless communication systems to broadcast an emergency alarm for exercising vigilance over an earthquake and a tsunami and urging evacuation of a specific area. Other such circumstances may be those where one or more than one responsible administrative ministries and/or agencies request wireless communication systems to broadcast an emergency alarm for exercising vigilance over a terror, a missile attack, an attack of biological weapons or toxic gas, a risk of widespread infection of a highly infectious disease, an accident of a nuclear power plant or the like and urging evacuation. However, high priority broadcast information is not limited to such emergency alarms. High priority broadcast information may be advertisement for a discount sale in a limited time zone that is requested to broadcast by a retailer.
High priority broadcast information may be requested to be or have to be conveyed reliably to mobile terminals at places deep in buildings and scarcely populated areas. However, no technique has been available to date to wireless communication systems for reliably broadcasting such high priority information.
As the second problem of the prior art, it is not possible to estimate the amount of the monetary loss that arises to a wireless communication system when it is forced to broadcast high priority information. Then, it is not possible for the wireless communication system to provide a reliable basis for the charge to be made to the party that requested to broadcast high priority information.

Wireless communication network and method for broadcasting high priority information using downlink common channels


This invention relates to the configuration of a mounting base and a method of mounting objects to hard surfaces using the combination of at least one anchoring screw, bolt, rod, or assembly; one mounting base; and one chemical bonding material to perform the anchoring function.

Mounting equipment and other devices (for example but not limited to, shop or kitchen equipment, shelving, safes, etc.) typically require that anchoring devices be screwed, nailed, drilled, or otherwise permanently fixed into the surface to be mounted against. There are many solutions available to mount items of varying grade, duty, or weight, but all current solutions require that an anchoring device penetrate into the mounted surface, which permanently damages, weakens, marks, scars, and otherwise destroys, or renders less useful, the immediate area whereby the anchor penetrates.
Further, items that get mounted onto surfaces frequently need to be removed from the mounted area or relocated. Current devices and methods to mount items in this fashion do not consider or allow for the removal of the anchoring mechanism without materially damaging the mounted surface. Various patents disclose devices and methods to mount or anchor items to flat surfaces, but improvements are desired. For example, a common means of anchoring a large shop tool to the floor is to drill a series of large holes several inches deep into concrete, insert a concrete anchoring bolt, apply a very large amount of outward and/or upward pressure within the drilled hole of the concrete by screwing down the anchor bolt into the concrete hole. This method weakens the concrete surface and makes it vulnerable to a variety of subsequent damage. And when the shop tool needs to be relocated, the anchoring bolt must be either ripped out of the floor (further damaging the surface) or cut flush to the floor, thus rendering that specific area less useful or desirable for future uses.
Also, many items that need to be mounted to flat surfaces do not get mounted because either the existing mounting options require too much time and resources to complete, or their owners do not desire to damage the flat surfaces required to mount the items. Lack of a reliable mounting solution that addresses customers' desire to quickly mount items while also allowing for a means to quickly remove or relocate the mounting apparatus when needed, ends up raising a variety of otherwise low to negligible risks (if the said equipment had been mounted), including risk of injury, death, damage, and theft. For example, safes need to be mounted to a strong surface in order to effectively reduce the risk of theft. But many owners of safes do not anchor them at all because of the high degree of time and resources needed to install them, as well as the destructive nature of conventional mounting options. This scenario also applies to many types of equipment that should be mounted but generally do not get mounted. For example, air compressors, grinders, drill presses, sanders, benches, picnic tables, event tents and awnings often fall into this scenario.

No-drill permanent-like surface mounting device


A semiconductor memory includes a memory cell array area provided with first and second memory cells and having a first active area and a first element isolation area constituting a line & space structure, and having a floating gate electrode and a control gate electrode in the first active area, a word line contact area adjacent to the memory cell array area and having a second active area, first and second word lines with a metal silicide structure, functioning respectively as the control gate electrodes of the first and second memory cells and arranged to straddle the memory cell array area and the word line contact area. A dummy gate electrode is arranged just below the first and second word lines in the second active area.

1. Field of the Invention
The present invention relates to a base structure of an end area of a word line of a semiconductor memory device.
2. Description of the Related Art
In recent years, in a semiconductor memory device such as a NAND type nonvolatile semiconductor memory device, a space between adjacent word lines (control gate lines) having a line & space structure has become narrow in accordance with the increase in capacity. For this reason, the space between the word lines is not completely filled with insulating materials, so that a void is easily formed in the space between the word lines. In some cases, the void extends to an end area of the word line along the word line.
The end area of the word line has a structure in which the distance between the word lines broadens in order to secure an area for providing each contact hole to the word lines.
For instance, a tip of each word line shifts little by little in an extending direction of the word line, and a pattern of the end area of the word line, as a whole, results in a single-edged shape or a double-edged shape. In addition, a fringe is formed at the end area of the word line.
For this reason, in some cases, an opening is formed on the void in the end area of the word line.
On the other hand, conventionally, in the NAND type or NOR type nonvolatile memory device, low resistance of the word line is attained by constituting an upper portion of the word line with tungsten silicide (WSi), however, in recent years, for further low resistance, for instance, employment of the silicide structure by using cobalt is started (for instance, refer to Jpn. Pat. Appln. KOKAI Publication No. 2007-73887).
Formation of the silicide structure by using cobalt uses a process in which, unlike the conventional formation of tungsten silicide, cobalt metal is deposited on a conductive polysilicon film, silicide is formed by reacting the cobalt metal with the polysilicon film by heat treatment, and unreacted cobalt metal is removed by wet etching.
Here, when the opening is formed in the void, dissolved liquid of metal silicide generated at the time of wet etching flows into the void via the opening, and remains in the void.
The dissolved liquid of the remaining metal silicide in the void becomes a metal ion and moves in an insulating film when high voltage is applied between two word lines which sandwich the dissolved liquid therebetween, thereby causing a short-circuit between these two word lines.
Therefore, in order to improve the reliability of the semiconductor memory device, a new technique for preventing such phenomenon must be developed.

Semiconductor memory device and method of fabricating the same


The invention provides a polishing composition comprising fumed alumina, alpha alumina, silica, a nonionic surfactant, a metal chelating organic acid, and a liquid carrier. The invention further provides a method of chemically-mechanically polishing a substrate comprising contacting a substrate with a polishing pad and the chemical-mechanical polishing composition, and abrading at least a portion of the substrate to polish the substrate.

The demand for increased storage capacity in memory or rigid disks and the trend towards miniaturization of memory or rigid disks (due to the requirement for smaller hard drives in computer equipment) continues to emphasize the importance of the memory or rigid disk manufacturing process, including the planarization or polishing of such disks for ensuring maximal performance. While there exist several chemical-mechanical polishing (CMP) compositions and methods for use in conjunction with semiconductor device manufacture, few conventional CMP methods or commercially available CMP compositions are well-suited for the planarization or polishing of memory or rigid disks.
As the demand for increased storage capacity has increased, so has the need for improved processes for the polishing of such memory or rigid disks. The term "memory or rigid disk" refers to any magnetic disk, hard disk, rigid disk, or memory disk for retaining information in electromagnetic form. The memory or rigid disk typically has a surface that comprises nickel-phosphorus, but the memory or rigid disk surface can comprise any other suitable material. The planarity of the memory or rigid disks must be improved, as the distance between the recording head of a disk drive and the surface of the memory or rigid disk has decreased. Reduction of defectivity of the memory or rigid disk, that is, the reduction of surface roughness, is necessary to increase recording density. In order to increase recording density, recording density per unit area on the memory or rigid disk must also be increased.
During the polishing of a memory or rigid disk, typically the edges of the disk receive a higher pressure from the polishing tool than the remaining surface area of the disk. Typically, polishing is performed using a combination of an abrasive, a polishing pad, and a liquid carrier, in which the abrasive may be suspended in the liquid carrier, or may be affixed to the surface of the pad. As the polishing process mainly consists of mechanical abrasion of the disk by the abrasive and/or pad, in conjunction with the action of chemicals that may be present, and the rate of abrasion is at least in part a function of pressure applied, the edges of the disk experience a higher rate of abrasion than the rest of the disk. This leads to the formation of a curved, or rounded, contour at the edges of the disk, known in the art as rub-off or dub-off. Such rounded areas on a disk are unsuitable for recording. Thus, if the amount of rub-off can be reduced, the recording capacity for a disk can be increased.
Therefore, considerable effort has been expended in a search for improved processes for the uniform polishing of memory or rigid disks. For example, U.S. Pat. No. 6,488,729 discloses a polishing composition comprising a polishing material, a polishing accelerator, hydroxypropyl cellulose or hydroxyalkyl alkyl cellulose, and water. U.S. Pat. No. 6,645,051 discloses a polishing composition for a memory hard disk comprising a polyoxyethylene polyoxypropylene alkyl ether or a polyoxyethylene polyoxypropylene copolymer, an inorganic or organic acid, an abrasive, and water.
There remains a need, however, for other compositions and methods for planarizing or polishing memory or rigid disks at a high rate, while minimizing surface defectivity. The invention provides such a composition and method. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

This patent is subject to a terminal disclaimer.


The present invention is an ignition control system for an engine having at least one combustion chamber and an ignition element for initiating combustion in the chamber. As one aspect of the ignition control, a switching circuit is provided for controlling the firing of the ignition element based upon either a signal received from a mechanism which detects and outputs a first firing timing signal or a computing mechanism which outputs a second firing timing signal based upon the first firing timing signal. As a second aspect of the ignition control, ignition elements are paired and fired together. In this arrangement, the ignition control includes a mechanism for counting outputted firing signals and assigning them values. These values are used to control the firing of the pairs of ignition elements, permitting the pairs of elements to be fired such that combustion initiation in individual combustion chambers corresponding is controllable.

Watercraft powered by inboard or outboard motors typically include an electrical system. The motor includes a water propulsion device which is powered by an internal combustion engine. As is well known, an ignition system is utilized to fire one or more ignition elements corresponding to each combustion chamber of the engine, igniting the air and fuel mixture in each combustion chamber of the engine.
It is very desirable to keep the engines used in these applications small and simple. To achieve this goal, use of a complex ignition system in which each ignition element is fired and controlled independently may be avoided. In particular, where the engine is of the four-cycle variety, a simple ignition system in which the ignition elements are paired is often used.
In a four-cycle engine, pairs of cylinders are generally arranged so that their pistons are in the same position but out of phase in the operating cycle. In other words, when the pistons corresponding to one pair of cylinders are both at top dead center, one cylinder is in the combustion portion of the cycle, while the other cylinder is in the exhaust portion of the cycle.
In the above-described arrangement where the ignition elements are paired, the ignition elements corresponding to a pair of cylinders are fired at the same time. To accomplish ignition in both cylinders, both ignition elements are fired every half-cycle. This arrangement permits the use of a single coil for both ignition elements, and eliminates the requirement that a separate firing timing signal be calculated and provided for the ignition element associated with each cylinder.
In some situations, it is desirable to disable one or more of the cylinders of an engine without completely shutting down the engine. For example, it may be desirable to disable one or more cylinders to prevent excessive engine speed or reduce engine temperature.
The above-stated ignition system, while being simple, has a drawback associated with a cylinder disabling function. Referring to FIG. 12(b), when it is desired to disable one cylinder, at least two cylinders must be disabled, since the ignition system permits only the turning on and off of the ignition signal associated with the pair of ignition element associated with two cylinders. In addition, if it is desirable to disable more than two cylinders, then four cylinders must be disabled. In the event the engine is of the four cylinder variety, the engine is shut down in this instance.
In either event, the ability of the ignition system to disable cylinders in only pairs can be counterproductive in achieving the goals desired by disabling cylinders. For example, if a slight reduction in engine speed is desired to prevent high engine speed, disabling two cylinders (instead of just one) may cause such a drop in power that the engine stalls or the like. In that instance where the engine is powering a boat, then the user of the boat may be stranded on the water.
An improved ignition system which overcomes the above-stated problems is desired.

Ignition control system for marine engine


A patch radiator suitable for operation with circular or dual linear polarizations is described. The patch radiator includes a patch antenna element and a pair of excitation circuits. The excitation circuits include a feed line and a turning circuit configured such that a single feed line enables independent operation of each polarization. This allows for the operation of the patch and therefore array as either linear, slant, elliptical, or circular polarization.

As is known in the art, a so-called patch antenna element (also referred to as "a patch element" or more simply "a patch") is a basic building block a number of different types of phased array antenna including so-called panel phased arrays (or panel arrays) such as the types described in U.S. Pat. Nos. 7,348,932; 7,671,696; and 8,279,131, all of which are assigned to the assignee of the present application. The patch element is integrated within a panel array to allow for the use of low cost printed wiring board (PWB) processes in the manufacture of the panel array.
Referring now to FIG. 1, a conventional patch element 2 and feed circuit 3 are coupled to provide a conventional patch radiator 4. The patch element is provided from a conductor disposed on a first surface of a substrate. A slot 5 is etched or otherwise provided in the conductor. The feed circuit 4 is provided from a single feed line 7 disposed on a second opposite surface of the substrate. A first end of the feed line corresponds to an antenna feed port 4A and a second end of the feed line 4B is coupled to a ground plane through a conductive via. An open ended stub 8 is coupled to feed line 7 as is generally known. Patch radiator 4 is responsive to radio frequency (RF) signals having a single linear polarization.
In operation, an RF signal provided to the antenna feed port 4A is coupled via feed line 7 to the open ended stub 8 thereby illuminating slot 5, which in turn excites the patch 2. Similarly, signals provided to patch conductor 2 illuminate the slot 5 and are coupled via the open ended stub 8 and feed line 7 to the feed line antenna feed port 4A. Thus, the patch radiator 4 operates for both transmitting and receiving RF signals.
As mentioned above, however, patch radiator 4 can be used only for a single polarization. This is due to the topology of the patch element 2 and feed circuit 3. To support dual and/or circular polarization, a more complicated geometry is required as illustrated in FIG. 2.
Referring now to FIG. 2, to support dual and/or circular polarization in one type of conventional patch radiator, a feed circuit comprising four feed lines (and thus four antenna feed ports) is required. Essentially, the single stub described above in conjunction with FIG. 1 is split into two open ended stubs (e.g. one to excite vertically polarized RF signals and one to excite horizontally polarized RF signals). To support dual linear polarization, both stubs (for each excitation) are driven in phase. This is conventionally accomplished via a microwave power divider circuit (not shown in FIG. 2). Simple geometry dictates the need four feeds. The single polarization example (FIG. 1) places the open ended stub along the center line. However, it is not possible to place two perpendicular open ended stubs, each aligned to the center line without them being shorted to each other. Therefore two open ended stubs are required for each polarization
Circular polarization may be obtained by introducing a ninety (90) degree phase shift between signals provided to (or received from) the horizontal and vertical stubs. Such a 90 degree phase shift can be accomplished using a ninety (90) degree hybrid coupler (not shown in FIG. 2) or by controlling the phases independently in control circuitry (not shown in FIG. 2). Therefore, to extend the operation of a patch radiator from a single linear polarization to operation with dual linear or circular polarization requires the addition of much circuitry (e.g. a power divider or hybrid coupler) to the feed circuit.
In a phased array antenna in which space in limited, it is difficult to fit such additional circuitry (e.g. additional power divider or hybrid coupler circuitry) within a so-called unit cell which includes an antenna element (e.g. one or more patch elements) and the associated feed circuitry. It would, therefore, be desirable to provide a patch radiator operable for use with dual linear or circular polarization RF signals and which is compact enough for use in phased array antennas.

Dual linear and circularly polarized patch radiator


A trigger assembly for a crossbow or other weapon system. The trigger assembly includes a trigger arm coupled between a trigger and a sear. The trigger arm is not parallel to the line of fire, thereby allowing for increased mechanical advantage and a smoother, safer trigger pull. The trigger assembly incorporates various safety measures, including a dry fire mechanism which prevents the unintentional damaging and potentially dangerous release of the bowstring before an arrow is positioned on the rail of the crossbow. The trigger assembly allows for various adjustments to vary the trigger length and pull, while maintaining smoothness and preventing the unintentional or inadvertent release of the bowstring.

1. Field of the Invention
The present invention relates in general to a trigger assembly and, more particularly, to an adjustable trigger assembly for use in association with a crossbow.
2. Description of the Prior Art
Crossbows have been known for centuries. By allowing the shooter to mechanically retain the bow in a cocked position, the shooter is provided an advantage over a traditional archer who must utilize muscular force to retain the bow in the cocked position. In a typical crossbow assembly, a cocking mechanism is utilized whereby two hooks are applied to the bowstring to draw the bowstring rearward into engagement with a retainer pin or other device utilized to retain the bowstring in the cocked position until the trigger is pulled.
As crossbows typically utilize very strong limbs, the bowstring is under high tension. This tension requires firm engagement between the sear and the trigger assembly. Tension associated with prior art devices and the solid engagement of the sear with the trigger assembly often results in an undesirably hard and rough trigger pull. This tension associated with many prior art devices may also result in torsion of the trigger assembly, causing unanticipated early or late release of the string during the trigger pull. It would, therefore, be desirable to provide a trigger assembly which provided sufficient mechanical advantage and stability to allow for a comfortable, smooth and predictable lightweight trigger pull to maintain comfort and prevent unintentional launch of a projectile from the crossbow associated with torsion forces on the trigger. The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention.


A server system including a rack, motherboards and direct current (DC) transformation units is provided. Each of the motherboards is inserted on the rack, and generates a power on signal. Each of the DC transformation units is on the rack and receives a DC voltage. When each of the motherboards is electrically connect to the corresponding DC transformation unit, each of the DC transformation units generates a standby voltage and a standby voltage ready signal to the motherboard according to the DC voltage so that the motherboard enters a standby state according to the standby voltage ready signal. When the motherboard corresponding to each of the DC transformation unit generates the power on signal, the DC transformation unit receives the power on signal and generates an operating voltage and an operating voltage ready signal to the motherboard, and the motherboard is turned on according to the operating voltage ready signal.

1. Field of the Invention
The invention relates to a server system. Particularly, the invention relates to a server system having a direct current transformation unit and a voltage protection display function.
2. Description of Related Art
Generally, a power supply is used to supply an operating voltage for a server system. The current power supply generally receives an alternating current (AC) voltage of 100V-230V first, and then a transformer inside the power supply transforms the AC voltage into a direct current (DC) voltage. Then, the power supply transforms the DC voltage into a voltage of 12V, 5V or 3V to serve as the operating voltage of the server system.
However, each independent server requires a power supply for supplying power. Therefore, when a plurality of independent servers is configured in the server system, a same number of the power supplies corresponding to a number of the independent servers are simultaneously used. Therefore, efficiency of the server system is reduced, and circuit cost of the server system is increased.

Server system with direct current transformation units receiving power on signal and generating operating voltage and ready signal


An oil sampling apparatus for taking samples from either pressurized or non-pressurized oil sources is provided. The oil sampling apparatus includes a body configured to define a conduit therethrough, a vacuum passageway defined to extend through the body in fluid communication with the conduit, and a pressurized oil passageway defined to extend through the body in fluid communication with the conduit. The body further defines a rigid tube having a tube interior connectable between a source of pressurized oil and the pressurized oil passageway. A sample bottle is positionable adjacent to the body in fluid tight communication with the conduit and a manually operated vacuum pump is attached in fluid communication to the vacuum passageway to allow oil to be drawn from a non-pressurized oil source, through the conduit, and into the sample bottle. Oil from pressurized sources can be collected by allowing a needle positioned in the tube interior to trigger release of pressurized oil from the source of pressurized oil when connected to the source of pressurized oil.

The present invention relates to manually operated oil sampling equipment for retrieval of oil samples from industrial machinery. More particularly, the present invention relates to dual function oil sampling equipment able to retrieve and store oil samples from either a pressurized oil source or a non-pressurized oil source.
Large industrial vehicles are commonly used in the transportation, construction, or mining industries. Such vehicles require large amounts of lubricating oils to reduce friction of moving engine parts and maintain seals. Periodic replacement of the lubricating oil is necessary because the lubricating oil carbonizes (oil breakdown), changing its viscosity and other lubrication properties. In addition, periodic lubricating oil changes are desirable because the lubricating oil may become contaminated with foreign particles such as metal shavings from engine parts, greatly increasing engine wear.
However, given the high cost of lubricating oil, the difficulties in disposal of waste oil, and the substantial maintenance time required for lubricating oil changes, it is highly desirable to maximize the time between lubricating oil changes. Simply setting periodic times for lubricating oil changes may permit unnecessary engine wear if the lubricating oil is contaminated before a scheduled oil change, or waste time and money if the oil is still usable at the time of the scheduled oil change. One method for ensuring that lubricating oil in industrial machinery is only replaced when necessary involves a program of lubricating oil sample retrieval. (See, for example, U.S. Pat. No. 4,548,088 which describes an oil sampling system). An oil sample is periodically taken, analyzed, and based on that analysis a complete lubricating oil change may be ordered. With this program, oil is only replaced when required, not when determined by an inflexible schedule.
In accordance with the present invention, an oil sampling apparatus suitable for periodic retrieval of lubricating oil samples is provided. The oil sampling apparatus of the present invention is designed to accommodate withdrawal of an oil sample from a pressurized oil source (for example, an idling internal combustion engine) or can alternatively be used to manually pump an oil sample from an unpressurized oil source. The apparatus includes a body having an upper and a lower side, the body being configured to define a conduit therethrough extending between the upper and lower sides. Both a vacuum passageway and a pressurized oil passageway are defined to extend through the body in fluid communication with the conduit. The body further defines a rigid tube having a tube interior connectable between a source of pressurized oil and the pressurized oil passageway.
A sample bottle, typically disposable, for accepting, holding, and storing an oil sample is positionable adjacent to the lower side of the body in fluid tight communication with the conduit. A manually operated vacuum pump is attached in fluid communication to the vacuum passageway, and a needle is positioned in the tube interior. The needle is configured to trigger release of pressurized oil from the source of pressurized oil when pushed into mating configuration with the source of pressurized oil.
A flexible tube is also provided for attachment to a non-pressurized source of oil. The flexible tube is insertible through the upper side of the body into the conduit for conveying oil between a non-pressurized oil source and the conduit, and a coupling system is attached to the upper side of the body to connect the flexible tube in fluid tight connection with the conduit. To prevent intake of atmospheric air into the conduit during operation of the manually operated vacuum pump, a removable seal for removably sealing the tube interior is provided. When the oil sampling apparatus is used for withdrawing non-pressurized oil samples, the tube and tube interior is closed off. This promotes the ability of an operator to draw a vacuum in the conduit, and consequently eases the task of drawing thick and viscous oil from a non-pressurized oil source through the flexible tubing and conduit, for storage in the sample bottle.
In an alternative embodiment, an oil sampling apparatus for taking an oil sample from either a pressurized or non-pressurized oil source and storing the oil sample in a removably attached sample bottle includes a body formed to define a conduit therethrough. The body further defines a vacuum passageway therethrough in fluid communication with the conduit and a pressurized oil passageway is defined to extend through the body in fluid communication with the conduit.
A mechanism for attaching a sample bottle to the body in fluid communication with the conduit is provided. A manually operated vacuum pump is attached in fluid communication to the vacuum passageway and a triggering release mechanism is provided for release of pressurized oil from a pressurized oil source when the triggering mechanism is in fluid communication with the pressurized oil passageway and a source of pressurized oil.
In addition to releasing pressurized oil, the apparatus of the present invention can recover non-pressurized oil. A mechanism for conveying oil between a non-pressurized oil source and the conduit is provided, along with a mechanism for coupling the conveying mechanism in fluid tight connection with the conduit. In operation, the pressurized oil passageway is sealed to promote drawing a vacuum in the conduit when oil is drawn by action of the manually operated vacuum pump from a non-pressurized oil source through the conveying mechanism into the conduit.
Typically, the triggering mechanism includes a rigid tube integrally defined to project from the body, the rigid tube having a tube interior connectable between a source of pressurized oil and the pressurized oil passageway. A needle is positioned in the tube interior, the needle being configured to trigger release of pressurized oil from the source of pressurized oil when connected to the source of pressurized oil. The needle may be formed to define a needle hole therethrough, the needle hole being connected in fluid communication with the pressurized oil passageway to allow passage of pressurized oil from the tube interior, through the needle hole, and into the pressurized oil passageway.
In a most preferred embodiment, the conveying mechanism includes a flexible tube having a proximal end positioned to extend into the conduit and a distal end positionable in fluid communication with a non-pressurized oil source. In this embodiment, the coupling mechanism may be include a stem attached to the body in fluid communication with the conduit, the stem extending outward from the body and allowing insertion therethrough of the flexible tube. A compression nut having a passageway therethrough to allow insertion therethrough of the flexible tube is also provided, with attachment of the compression nut to the stem compressing a compressible elastic washer positioned therebetween to hold the flexible tube in sealing engagment with the stem.
The present invention may be best understood by consideration of the following preferred embodiments and drawings, which present the best mode of practicing the invention as presently perceived.

Dual use pressurized and unpressurized oil sampling apparatus


Systems and methods for removing material, e.g., linters, from seeds, e.g., ginned cottonseeds, are provided. The systems and methods involve rotating the seeds in a rotatable drum having a plurality of longitudinal brushes. The centrifugal force created by the rotation of the drum and the plurality of longitudinal brushes urge the seeds against an interior surface of the drum that is lined with a brush insert. In this way, work is performed that removes the material from the exterior of the seeds. The material is removed using reduced pressure and the processed seeds are removed. The system may include a brush insert that is easily removed from the rotatable drum. Other systems and methods are disclosed.

The present disclosure relates generally to processing cottonseeds or other seeds, and more particularly, but not by way of limitation, to cottonseed delinters and methods.
Cotton is said to have been in use since prehistoric times and remains an important product in the world today for many purposes. Cotton grows in a cotton boll, which is a protective capsule, around the seeds of the cotton plant. With the Industrial Revolution, cotton began to be separated from the cottonseed with a cotton gin. Yet, after ginning the cottonseed, cotton linters (or cotton wool) remain on the cottonseed. Linters are fine, silky fibers that are typically less than ¼ of an inch (6.3 mm) or less than ⅛ of an inch (3 mm) long. Linters have a unique lumen and have many uses and potential uses. Linters are different than the longer staple lint and are not simply short pieces of residual staple lint. At times, other seeds also need removal of an exterior portion.

The United States of America Secretary of Agriculture


Provided is a zinc-plated steel sheet for hot pressing having outstanding surface characteristics, comprising: a steel foundation plate comprising a metal surface diffusion layer of which the Gibbs free energy reduction per mole of oxygen during oxidation is less than that of Cr, an aluminum-rich layer containing at least 30 wt. % of aluminum formed on the surface diffusion layer, and a zinc plating layer formed on the aluminum-rich layer. In this way, a metal having a low affinity for oxygen is coated to an effective thickness prior to annealing and thus the creation of annealing oxides at the surface of the steel sheet is suppressed and a uniform zinc plating layer is formed, and alloying of the zinc plating layer is promoted during press-processing heat treatment. Cracking in the steel foundation plate during hot press molding is prevented.

1. Technical Field
The present invention relates to a zinc-plated steel sheet for hot press forming and more particularly, to a zinc-plated steel sheet for hot pressing having excellent surface characteristics able to secure a stable plating layer by preventing deterioration of the plating layer during hot press forming, a hot-pressed part using the same, and a method of manufacturing thereof.
2. Background Art
Recently, demand for high-strength steel sheets for the purpose of improving vehicle fuel economy to meet with environmental protection regulations has rapidly increased. In accordance with the strengthening of automotive steel sheets, wear and fracturing may occur during press forming, and the formation of complex-shaped products may be difficult. Therefore, in order to resolve such limitations, the production of products by hot pressing, in which a steel sheet is heated to be molded in a hot state, has greatly increased.
A steel sheet for hot pressing is generally subjected to hot press forming in a temperature range of 800° C. to 900° C., and a surface of the steel sheet may be oxidized, thereby generating scaling. Therefore, a separate process for removing scaling after product formation, such as shot blasting, is required, such that product corrosion resistance may also be inferior to that of a plated material.
Therefore, in order to address such limitations, products as that of U.S. Pat. No. 6,296,805, in which aluminum (Al)-based plating is performed on a steel sheet surface to maintain a plating layer, while formation of an oxidation reaction of the steel sheet surface in a heating furnace is prevented and corrosion resistance is increased through the formation of a passive Al film, have been developed and commercialized.
However, with respect to the Al-plated material, heat resistance at high temperatures is excellent, while corrosion resistance may be inferior to that of a zinc (Zn)-plated steel sheet formed through a sacrificial anode method and manufacturing costs may also increase.
Since Zn high-temperature heat resistance is significantly inferior to that of Al, a plating layer of a Zn-plated steel sheet manufactured via a typical manufacturing method may be non-uniformly formed due to alloying of a Zn layer and high-temperature oxidation in a high temperature range of 800° C. to 900° C., and a ratio of Zn in the plating layer may be decreased to less than 30%. Therefore, its functionality as a plating material may be reduced in terms of corrosion resistance.

Zinc-plated steel sheet for hot pressing having outstanding surface characteristics, hot-pressed moulded parts obtained using the same, and a production method for the same


A cutterhead for a string trimmer having a rotatable drive shaft is adapted to hold and meter a cutting filament during operational use thereof. The cutterhead includes a disc-like carrier fixedly connected to one end of the drive shaft to permit the carrier to rotate about a rotational axis. The carrier has a peripheral edge and a peripherally extending outer wall approximately perpendicular to the carrier along the peripheral edge. The outer wall defines a space for accommodating the cutting filament in the cutterhead and has a guide eyelet disposed therein to define a pass-through opening for guiding the filament from the space to the outside of the cutterhead where a segment of the filament extends radially outwardly from the outer wall to define a cutting plane when the drive shaft rotates. The guide eyelet is made of wear-resistant material and is adapted to the diameter of the cutting filament. A stop is disposed in the cutting plane for receiving the segment of the cutting filament thereagainst when the segment strikes an obstacle and is deflected during operation of the string trimmer. The stop is disposed radially forward of the outer wall next to the pass-through opening.

In cutterheads, it is known to make the carrier together with the outer wall of the cutterhead out of light material such as plastic, light metal or the like to obtain a reduced weight. A supply spool for the cutting filament is arranged in the cutterhead. An actuation element extends through the spool and actuates an indexing device for metering the cutting filament from the spool. The indexing device is defined by latch noses displaced in elevation and located between the actuating element and the supply spool. By pressing down the actuating element, the latch connection is released in the one latching plane and a relative movement between the cutterhead and the supply spool is made possible until the latch element comes into contact engagement in the second latch plane. The cutting filament is unwound from the spool by means of this relative movement and moves through the pass-through opening provided in the outer wall.
If the cutting filament encounters an obstruction in the cutting plane, then the filament is deflected in a direction opposite to the direction of rotation whereby an intense kink load is applied to the cutting filament at the exit edge of the pass-through opening. The wall of the pass-through opening also receives a corresponding load because of this kink load on the cutting filament which is usually made of plastic. The cutting filament can be sheared off at the elevation of the pass-through opening when the load is too great. This can lead to disturbances of the indexing device because the remaining length of the cutting filament is too short. An unwinding of the cutting filament is no longer obtainable notwithstanding a press-down displacement of the actuating element. To eliminate the disturbance, the cutterhead must be opened which is time consuming and causes an interruption of work. In addition, the intense loads on the wall of the pass-through opening lead to a considerable wear thereby causing the pass-through opening to widen which is associated with a reduction in the guidance of the cutting filament. This too can lead to considerable disturbances of the indexing device. A welding of the cutting filament in the pass-through opening caused by wear cannot be excluded especially in the case of cutterheads made of plastic.


A power electronics assembly may include a power component having a thermally and electrically conductive surface; a printed circuit board having a slot; and a bussing element having a protrusion that directly contacts the thermally and electrically conductive surface of the power component via the slot of the printed circuit board, the printed circuit board being disposed between the power component and the bussing element.

Modern power electronic components such as metal-oxide-semiconductor field effect transistors (MOSFETs) are capable of very high levels of current if they are thermally managed. To use the full capability of these components, they are typically cooled through the mounting surface on the base of the component. That is, they are typically cooled through the same surface which comprises the electrical connection. The most common circuit board construction, known as FR-4, is a composite (typically several layers) of glass-reinforced epoxy where circuit traces are printed with copper foil. The epoxy-glass material has low thermal conductivity and is thus not capable of removing enough heat to allow modern power electronic components to operate to their full potential.
In high power applications, circuit board construction typically utilizes a metal (and thus electrically conductive) substrate coated with a thin layer of dielectric (electrical insulation), upon which conductive traces are printed in copper. This type of construction is known as Insulated Metal Substrate (IMS). While IMS construction alleviates the thermal management problem due to the high thermal conductivity of the metal substrate being separated from the component by only a thin layer of dielectric, it includes additional constraints.
First, these constraints include limitations against multilayer construction. This constraint severely limits the circuit complexity that can be implemented on an IMS circuit board since every location where circuit traces must cross without being connected demands a physical jumper component to act as a bridge.
Second, these constraints include limitations against fine-pitch components. Heavy copper thickness is required in the IMS circuit traces to carry high levels of current from power electronic components. This heavy copper thickness limits the fine detail that can be achieved in the printing or etching process. As a result, fine pitch components, for example on the order of 0.5 mm pitch between component connections, cannot be implemented on the same circuit board. This forces designers to use multiple circuit boards, placing the small components, those with fine pitch connections, and the complex circuits on a classical FR-4 or similar type circuit board, typically with multiple layers to assist in routing the complex circuitry. The designer would then place the power electronic components, along with larger components with coarser pitch (e.g., 1 mm or greater), and simple circuits with only a few bridging points, on an IMS circuit board. Finally, an interconnecting means is required between the IMS board and the FR-4 board, demanding even more space and cost.
Third, these constraints include a limited supply base. IMS boards must be procured from a limited supply base and are thus even more expensive to procure than would be expected from their already more expensive materials. IMS boards require special processing for assembly and are thus more expensive to process due to the limited number of assembly suppliers that process such boards.
Fourth, these constraints include lack of "quick-turn" suppliers. Classical multi-layer FR-4 printed circuit boards can be procured to a custom design within days from an established base of quick-turn suppliers. IMS circuit boards require a minimum of several weeks to be delivered for a prototype and thus slow the product development process and limit the number of prototypes that can be executed in a program.

Bussing and printed circuit board integration with power electronics


A communication system is provided that, if a large number of small cells are installed, is capable of configuring an operation suitable for small cells through simple operation and administration. If a small cell installed in Step ST1401 judges in Step ST1403 that a coverage macro cell, which includes the small cell in the coverage of the coverage macro cell, is present as a result of neighbor cell search in Step ST1402, notifies the coverage macro cell and another neighbor cell of its own capability in Steps ST1404 and 1405. The coverage macro cell selects a configuration parameter suitable for the capability of the small cell in Step ST1406 and notifies the small cell in Step ST1407. The small cell recognizes an operation mode configured by the coverage macro cell from the configuration parameter notified from the coverage macro cell, and then, starts operating in the operation mode.

Commercial service of a wideband code division multiple access (W-CDMA) system among so-called third-generation communication systems has been offered in Japan since 2001. In addition, high speed downlink packet access (HSDPA) service for achieving higher-speed data transmission using a downlink has been offered by adding a channel for packet transmission (high speed-downlink shared channel (HS-DSCH)) to the downlink (dedicated data channel, dedicated control channel). Further, in order to increase the speed of data transmission in an uplink direction, service of a high speed uplink packet access (HSUPA) system has been offered. W-CDMA is a communication system defined by the 3rd generation partnership project (3GPP) that is the standard organization regarding the mobile communication system, where the specifications of Release 10 version are produced.
Further, 3GPP is studying new communication systems referred to as long term evolution (LTE) regarding radio sections and system architecture evolution (SAE) regarding the overall system configuration including a core network and a radio access network (hereinafter, collectively referred to as a network as well) as communication systems independent of W-CDMA. This communication system is also referred to as 3.9 generation (3.9 G) system.
In the LTE, an access scheme, a radio channel configuration, and a protocol are totally different from those of the W-CDMA (HSDPA/HSUPA). For example, as to the access scheme, code division multiple access is used in the W-CDMA, whereas in the LTE, orthogonal frequency division multiplexing (OFDM) is used in a downlink direction and single carrier frequency division multiple access (SC-FDMA) is used in an uplink direction. In addition, the bandwidth is 5 MHz in the W-CDMA, while in the LTE, the bandwidth can be selected from 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz per base station. Further, differently from the W-CDMA, circuit switching is not provided but a packet communication system is only provided in the LTE.
In the LTE, a communication system is configured with a new core network different from the general packet radio service (GPRS) being the core network of the W-CDMA, and thus, the radio access network of the LTE is defined as a radio access network independent of the W-CDMA network.
Therefore, for differentiation from the W-CDMA communication system, a core network and a radio access network are referred to as an evolved packet core (EPC) and an evolved universal terrestrial radio access network (E-UTRAN), respectively, in the LTE communication system. Also in the radio access network, the base station that communicates with a mobile terminal (user equipment (UE)) being a communication terminal device is referred to as an E-UTRAN NodeB (eNB). The EPC functions as a radio network controller that exchanges control data and user data with a plurality of base stations. The EPC is also referred to as an access gateway (aGW). The system formed of the EPC and E-UTRAN is referred to as an evolved packet system (EPS).
Unicast service and evolved multimedia broadcast multicast service (E-MBMS service) are provided in the LTE communication system. The E-MBMS service is broadcast multimedia service. The E-MBMS service is merely referred to as MBMS in some cases. Bulk broadcast contents such as news, weather forecast, and mobile broadcast are transmitted to a plurality of user equipments in the E-MBMS service. This is also referred to as point to multipoint service.
Non-Patent Document 1 (Chapter 4) describes the current decisions by 3GPP regarding an overall architecture in the LTE system. The overall architecture will be described with reference to FIG. 1. FIG. 1 is a diagram illustrating the configuration of the LTE communication system. With reference to FIG. 1, the E-UTRAN is composed of one or a plurality of base stations 102, provided that a control protocol for a user equipment 101 such as a radio resource control (RRC), and user planes such as a packet data convergence protocol (PDCP), radio link control (RLC), medium access control (MAC), or physical layer (PHY) are ended in the base station 102.
The base stations 102 perform scheduling and transmission of a paging signal (also referred to as paging messages) notified from a mobility management entity (MME) 103. The base stations 102 are connected to each other by means of an X2 interface. In addition, the base stations 102 are connected to an evolved packet core (EPC) by means of an S1 interface. More specifically, the base station 102 is connected to the mobility management entity (MME) 103 by means of an S1_MME interface and connected to a serving gateway (S-GW) 104 by means of an S1_U interface.
The MME 103 distributes the paging signal to a plurality of or a single base station 102. In addition, the MME 103 performs mobility control of an idle state. When the user equipment is in the idle state and an active state, the MME 103 manages a list of tracking areas.
The S-GW 104 transmits/receives user data to/from one or a plurality of base stations 102. The S-GW 104 serves as a local mobility anchor point in handover between base stations. Moreover, a PDN gateway (P-GW) is provided in the EPC. The P-GW performs per-user packet filtering and UE-ID address allocation.
The control protocol RRC between the user equipment 101 and the base station 102 performs broadcast, paging, RRC connection management, and the like. The states of the base station and the user equipment in RRC are classified into RRC_IDLE and RRC_CONNECTED. In RRC_IDLE, public land mobile network (PLMN) selection, system information (SI) broadcast, paging, cell reselection, mobility, and the like are performed. In RRC_CONNECTED, the user equipment has RRC connection and is capable of transmitting/receiving data to/from a network. In RRC_CONNECTED, for example, handover (HO) and measurement of a neighbor cell are performed.
The current decisions by 3GPP regarding the frame configuration in the LTE system described in Non-Patent Document 1 (Chapter 5) will be described with reference to FIG. 2. FIG. 2 is a diagram illustrating the configuration of a radio frame used in the LTE communication system. With reference to FIG. 2, one radio frame is 10 ms. The radio frame is divided into ten equally sized subframes. The subframe is divided into two equally sized slots. The first and sixth subframes contain a downlink synchronization signal (SS) per each radio frame. The synchronization signals are classified into a primary synchronization signal (P-SS) and a secondary synchronization signal (S-SS).
Multiplexing of channels for multimedia broadcast multicast service single frequency network (MBSFN) and for non-MBSFN is performed on a per-subframe basis. MBSFN transmission is the simulcast transmission technique realized by simultaneous transmission of the same waveforms from a plurality of cells. The MBSFN transmission from a plurality of cells in the MBSFN area is seen as a single transmission by a user equipment. The MBSFN is a network that supports such MBSFN transmission. Hereinafter, a subframe for MBSFN transmission is referred to as an MBSFN subframe.
Non-Patent Document 2 describes a signaling example when MBSFN subframes are allocated. FIG. 3 is a diagram illustrating the configuration of the MBSFN frame. As shown in FIG. 3, the radio frames including the MBSFN subframes are allocated per radio frame allocation period. The MBSFN subframe is a subframe allocated for the MBSFN in a radio frame defined by the allocation period and the allocation offset (radio frame allocation offset), which serves to transmit multimedia data. The radio frame satisfying Equation (1) below is a radio frame including the MBSFN subframes.SFN mod radioFrameAllocationPeriod=radioFrameAllocationOffset  (1)
The MBSFN subframe is allocated with six bits. With reference to FIG. 3, the leftmost bit defines the MBSFN allocation for the second subframe (#1). The second hit, third bit, fourth bit, fifth bit, and sixth-bit from the left define the MBSFN allocation for the third subframe (#2), fourth subframe (#3), seventh subframe (#6), eighth subframe (#7), and ninth subframe (#8), respectively. The case where the bit indicates "one" represents that a corresponding subframe is allocated for the MBSFN.
Non-Patent Document 1 (Chapter 5) describes the current decisions by 3GPP regarding the channel configuration in the LTE system. It is assumed that the same channel configuration is used in a closed subscriber group (CSG) cell as that of a non-CSG cell. Physical channels are described with reference to FIG. 4. FIG. 4 is a diagram illustrating physical channels used in the LTE communication system.
With reference to FIG. 4, a physical broadcast channel (PBCH) 401 is a channel for downlink transmission from the base station 102 to the user equipment 101. A BCH transport block is mapped to four subframes within a 40 ms interval. There is no explicit signaling indicating 40 ms timing.
A physical control format indicator channel (PCFICH) 402 is a channel for downlink transmission from the base station 102 to the user equipment 101. The PCFICH notifies the number of OFDM symbols used for PDCCHs from the base station 102 to the user equipment 101. The PCFICH is transmitted in each subframe.
A physical downlink control channel (PDCCH) 403 is a channel for downlink transmission from the base station 102 to the user equipment 101. The PDCCH notifies the resource allocation information for downlink shared channel (DL-SCH) being one of the transport channels shown in FIG. 5 described below, resource allocation information for a paging channel (PCH) being one of the transport channels shown in FIG. 5, and hybrid automatic repeat request (HARQ) information related to DL-SCH. The PDCCH carries an uplink scheduling grant. The PDCCH carries acknowledgement (Ack)/negative acknowledgement (Nack) that is a response signal to uplink transmission. The PDCCH is referred to as an L1/L2 control signal as well.
A physical downlink shared channel (PDSCH) 404 is a channel for downlink transmission from the base station 102 to the user equipment 101. A downlink shared channel (DL-SCH) that is a transport channel and a PCH that is a transport channel are mapped to the PDSCH.
A physical multicast channel (PMCH) 405 is a channel for downlink transmission from the base station 102 to the user equipment 101. A multicast channel (MCH) that is a transport channel is mapped to the PMCH.
A physical uplink control channel (PUCCH) 406 is a channel for uplink transmission from the user equipment 101 to the base station 102. The PUCCH carries Ack/Nack that is a response signal to downlink transmission. The PUCCH carries a channel quality indicator (CQI) report. The CQI is quality information indicating the quality of received data or channel quality. In addition, the PUCCH carries a scheduling request (SR).
A physical uplink shared channel (PUSCH) 407 is a channel for uplink transmission from the user equipment 101 to the base station 102. An uplink shared channel (UL-SCH) that is one of the transport channels shown in FIG. 5 is mapped to the PUSCH.
A physical hybrid ARQ indicator channel (PHICH) 408 is a channel for downlink transmission from the base station 102 to the user equipment 101. The PHICH carries Ack/Nack that is a response signal to uplink transmission. A physical random access channel (PRACH) 409 is a channel for uplink transmission from the user equipment 101 to the base station 102. The PRACH carries a random access preamble.
A downlink reference signal (RS) is a known symbol in the LTE communication system. The following five types of downlink reference signals are defined: cell-specific reference signals (CRS), MBSFN reference signals, data demodulation reference signal (DM-RS) being UE-specific reference signals, positioning reference signals (PRS), and channel-state information reference signals (CSI-RS). The physical layer measurement objects of a user equipment include reference signal received power (RSRP).
The transport channels described in Non-Patent Document 1 (Chapter 5) will be described with reference to FIG. 5. FIG. 5 is a diagram illustrating transport channels used in the LTE communication system. Part (A) of FIG. 5 shows mapping between downlink transport channels and downlink physical channels. Part (B) of FIG. 5 shows mapping between uplink transport channels and uplink physical channels.
A broadcast channel (BCH) among the downlink transport channels shown in Part (A) of FIG. 5 is broadcast to the entire coverage of a base station (cell). The BCH is mapped to the physical broadcast channel (PBCH).
Retransmission control according to a hybrid ARQ (HARQ) is applied to a downlink shared channel (DL-SCH). The DL-SCH can be broadcasted to the entire coverage of the base station (cell). The DL-SCH supports dynamic or semi-static resource allocation. The semi-static resource allocation is also referred to as persistent scheduling. The DL-SCH supports discontinuous reception (DRX) of a user equipment for enabling the user equipment to save power. The DL-SCH is mapped to the physical downlink shared channel (PDSCH).
The paging channel (PCH) supports DRX of the user equipment for enabling the user equipment to save power. The PCH is required to be broadcast to the entire coverage of the base station (cell). The PCH is mapped to physical resources such as the physical downlink shared channel (PDSCH) that can be used dynamically for traffic.
The multicast channel (MCH) is used for broadcast to the entire coverage of the base station (cell). The MCH supports SFN combining of MBMS services (MTCH and MCCH) in multi-cell transmission. The MCH supports semi-static resource allocation. The MCH is mapped to the PMCH.
Retransmission control according to a hybrid ARQ (HARQ) is applied to an uplink shared channel (UL-SCH) among the uplink transport channels shown in Part (B) of FIG. 5. The UL-SCH supports dynamic or semi-static resource allocation. The UL-SCH is mapped to the physical uplink shared channel (PUSCH).
A random access channel (RACH) shown in Part (B) of FIG. 5 is limited to control information. The RACH involves a collision risk. The RACH is mapped to the physical random access channel (PRACH).
The HARQ will be described. The HARQ is the technique for improving the communication quality of a channel by combination of automatic repeat request (ARQ) and error correction (forward error correction). The HARQ is advantageous in that error correction functions effectively by retransmission even for a channel whose communication quality changes. In particular, it is also possible to achieve further quality improvement in retransmission through combination of the reception results of the first transmission and the reception results of the retransmission.
An example of the retransmission method will be described. If the receiver fails to successfully decode the received data, in other words, if a cyclic redundancy check (CRC) error occurs (CRC=NG), the receiver transmits "Nack" to the transmitter. The transmitter that has received "Nack" retransmits the data. If the receiver successfully decodes the received data, in other words, if a CRC error does not occur (CRC=OK), the receiver transmits "AcK" to the transmitter. The transmitter that has received "Ack" transmits the next data.
Examples of the HARQ system include chase combining. In chase combining, the same data is transmitted in the first transmission and retransmission, which is the system for improving gains by combining the data of the first transmission and the data of the retransmission in retransmission. Chase combining is based on the idea that correct data is partially included even if the data of the first transmission contains an error, and highly accurate data transmission is enabled by combining the correct portions of the first transmission data and the retransmission data. Another example of the HARQ system is incremental redundancy (IR). The IR is aimed to increase redundancy, where a parity bit is transmitted in retransmission to increase the redundancy by combining the first transmission and retransmission, to thereby improve the quality by an error correction function.
The logical channels described in Non-Patent Document 1 (Chapter 6) will be described with reference to FIG. 6. FIG. 6 is a diagram illustrating logical channels used in an LTE communication system. Part (A) of FIG. 6 shows mapping between downlink logical channels and downlink transport channels. Part (B) of FIG. 6 shows mapping between uplink logical channels and uplink transport channels.
A broadcast control channel (BCCH) is a downlink channel for broadcast system control information. The BCCH that is a logical channel is mapped to the broadcast channel (BCH) or downlink shared channel (DL-SCH) that is a transport channel.
A paging control channel (PCCH) is a downlink channel for transmitting paging information and system information change notifications. The PCCH is used when the network does not know the cell location of a user equipment. The PCCH that is a logical channel is mapped to the paging channel (PCH) that is a transport channel.
A common control channel (CCCH) is a channel for transmission control information between user equipments and a base station. The CCCH is used in the case where the user equipments have no RRC connection with the network. In a downlink direction, the CCCH is mapped to the downlink shared channel (DL-SCH) that is a transport channel. In an uplink direction, the CCCH is mapped to the uplink shared channel (UL-SCH) that is a transport channel.
A multicast control channel (MCCH) is a downlink channel for point-to-multipoint transmission. The MCCH is used for transmission of MBMS control information for one or several MTCHs from a network to a user equipment. The MCCH is used only by a user equipment during reception of the MBMS. The MCCH is mapped to the multicast channel (MCH) that is a transport channel.
A dedicated control channel (DCCH) is a channel that transmits dedicated control information between a user equipment and a network on a point-to-point basis. The DCCH is used if the user equipment has an RRC connection. The DCCH is mapped to the uplink shared channel (UL-SCH) in uplink and mapped to the downlink shared channel (DL-SCH) in downlink.
A dedicated traffic channel (DTCH) is a point-to-point communication channel for transmission of user information to a dedicated user equipment. The DTCH exists in uplink as well as downlink. The DTCH is mapped to the uplink shared channel (UL-SCH) in uplink and mapped to the downlink shared channel (DL-SCH) in downlink.
A multicast traffic channel (MTCH) is a downlink channel for traffic data transmission from a network to a user equipment. The MTCH is a channel used only by a user equipment during reception of the MBMS. The MTCH is mapped to the multicast channel (MCH).
CGI represents a cell global identifier. ECGI represents an E-UTRAN cell global identifier. A closed subscriber group (CSG) cell is introduced in the LTE, and the long term evolution advanced (LTE-A) and universal mobile telecommunication system (UMTS) described below. The CSG cell will be described below (see Chapter 3.1 of Non-Patent Document 3).
The closed subscriber group (CSG) cell is a cell in which subscribers who are allowed to use are specified by an operator (also referred to as a "cell for specific subscribers"). The specified subscribers are allowed to access one or more cells of a public land mobile network (PLMN). One or more cells in which the specified subscribers are allowed access are referred to as "CSG cell(s)." Note that access is limited in the PLMN.
The CSG cell is part of the PLMN that broadcasts a specific CSG identity (CSG ID; CSG-ID) and broadcasts "TRUE" in a CSG indication. The authorized members of the subscriber group who have registered in advance access the CSG cells using the CSG-ID that is the access permission information.
The CSG-ID is broadcast by the CSG cell or cells. A plurality of CSG-IDs exist in the LTE communication system. The CSG-IDs are used by user equipments (UEs) for making access from CSG-related members easier.
The locations of user equipments are tracked on the basis of an area composed of one or more cells. The locations are tracked for enabling tracking the locations of user equipments and calling user equipments, in other words, incoming calling to user equipments even in an idle state. An area for tracking locations of user equipments is referred to as a tracking area.
The CSG whitelist is a list that may be stored in a universal subscriber identity module (USIM) in which all CSG IDs of the CSG cells to which the subscribers belong are recorded. The CSG whitelist may be merely referred to as a whitelist or an allowed CSG list as well. As to the access of user equipments through a CSG cell, the MME performs access control (see Chapter 22.214.171.124 of Non-Patent Document 4). Specific examples of the access of user equipments include attach, combined attach, detach, service request, and a tracking area update procedure (see Chapter 18.104.22.168 of Non-Patent Document 4).
Described below is the service types of a user equipment in an idle state (see Chapter 4.3 of Non-Patent Document 3). The service types of user equipments in an idle state include a limited service, normal service, and operator service. The limited service includes emergency calls, earthquake and tsunami warning system (ETWS), and commercial mobile alert system (CMAS) on an acceptable cell described below. The normal service is a public service on a suitable cell described below. The operator service includes a service for operators only on a reserved cell described below.
Described below is a "suitable cell". The "suitable cell" is a cell on which a UE may camp (Camp ON) to obtain normal service. Such a cell shall fulfill the following conditions (1) and (2).
(1) The cell is part of the selected PLMN or the registered PLMN, or part of the PLMN of an "equivalent PLMN list."
(2) According to the latest information provided by a non-access stratum (NAS), the cell shall further fulfill the following conditions (a) to (d):
(a) the cell is not a barred cell;
(b) the cell is part of a tracking area, not part of the list of "forbidden LAs for roaming," where the cell needs to fulfill (1) above;
(c) the cell shall fulfill the cell selection criteria; and
(d) for a cell specified as CSG cell by system information (SI), the CSG-ID is part of a "CSG whitelist" of the UE, that is, is contained in the CSG whitelist of the UE.
Described below is an "acceptable cell." The "acceptable cell" is the cell on which a UE may camp to obtain limited service. Such a cell shall fulfill all the following requirements (1) and (2).
(1) The cell is not a prohibited cell (also referred to as a "barred cell").
(2) The cell fulfills the cell selection criteria.
"Barred cell" is indicated in the system information. "Reserved cell" is indicated in the system information.
"Camping on a cell" represents the state where a UE has completed the cell selection or cell reselection process and the UE has selected a cell for monitoring the system information and paging information. The cell on which the UE camps may be referred to as a "serving cell."
3GPP is studying base stations referred to as Home-NodeB (Home-NB; HNB) and Home-eNodeB (Home-eNB; HeNB). HNB/HeNB is a base station for, for example, household, corporation, or commercial access service in UTRAN/E-UTRAN. Non-Patent Document 5 discloses three different modes of the access to the HeNB and HNB. Specifically, an open access mode, a closed access mode, and a hybrid access mode are disclosed.
The respective modes have the following characteristics. In the open access mode, the HeNB and HNB are operated as a normal cell of a normal operator. In the closed access mode, the HeNB and HNB are operated as a CSG cell. The CSG cell is a CSG cell where only CSG members are allowed access. In the hybrid access mode, the HeNB and HNB are operated as CSG cells where non-CSG members are allowed access at the same time. In other words, a cell in the hybrid access mode (also referred to as a hybrid cell) is the cell that supports both the open access mode and the closed access mode.
In 3GPP, among all physical cell identities (PCIs), there is a range of PCIs reserved by the network for use by CSG cells (see Chapter 10.5.1.1 of Non-Patent Document 1). Division of the PCI range is also referred to as PCI split. The information about PCI split (also referred to as PCI split information) is broadcast in the system information from a base station to user equipments being served thereby. To be served by a base station means to take the base station as a serving cell.
Non-Patent Document 6 discloses the basic operation of a user equipment using PCI split. The user equipment that does not have the PCI split information needs to perform cell search using all PCIs, for example, using all 504 codes. On the other hand, the user equipment that has the PCI split information is capable of performing cell search using the PCI split information.
Further, 3GPP is pursuing specifications standard of long term evolution advanced (LTE-A) as Release 10 (see Non-Patent Documents 7 and 8).
As to the LTE-A system, it is studied that a relay and a relay node (RN) are supported for achieving a high data rate, high cell-edge throughput, new coverage area, and the like. The relay node being a relay device is wirelessly connected to the radio-access network via a cell referred to as a donor cell (hereinafter, also referred to as a "Donor eNB; DeNB"). The network (NW)-to-relay node link shares the same frequency band with the network-to-UE link within the range of the donor cell. In this case, the UE supporting Release 8 of 3GPP is also connectable to the donor cell. The link between the donor cell and the relay node is referred to as a backhaul link, and the link between the relay node and the UE is referred to as an access link.
As the method of multiplexing a backhaul link in frequency division duplex (FDD), the transmission from a DeNB to an RN is performed at a downlink (DL) frequency band, and the transmission from an RN to a DeNB is performed at an uplink (UL) frequency band. As the method of dividing resources in a relay, a link from a DeNB to an RN and a link from an RN to a UE are time-division multiplexed at one frequency band, and a link from an RN to a DeNB and a link from a UE to an RN are also time-division multiplexed at one frequency band. In a relay, accordingly, the transmission of the relay is prevented from interfering the reception of its own relay.
Not only a normal eNB (macro cell) but also so-called local nodes such as pico eNB (pico cell), HeNB (HNB, CSG cell), node for hotzone cells, relay node, remote radio head (RRH), and repeater are studied in 3GPP. The network composed of various types of cells as described above is also referred to as a heterogeneous network (HetNet) in some cases.
The frequency bands (hereinafter, also referred to as "operating bands") usable for communication have been predetermined in the LTE. Non-Patent Document 9 describes the frequency bands.
Carrier aggregation (CA) is studied in the LTE-A system, in which two or more component carriers (CCs) are aggregated to support wider transmission bandwidths up to 100 MHz.
A UE supporting Release 8 or 9 of 3GPP, which supports LTE, is capable of transmission and reception on only one CC corresponding to one serving cell. Meanwhile, it is conceivable that a UE supporting Release 10 of 3GPP may have the capability of transmission and reception, only reception, or only transmission on a plurality of CCs corresponding to a plurality of serving cells at the same time.
Each CC employs the configuration of Release 8 or 9 of 3GPP, and the CA supports contiguous CCs, non-contiguous CCs, and CCs in different frequency bandwidths. The UE cannot configure uplink CCs (UL CCs) equal to or more than the number of downlink CCs (DL CCs). The CCs configured by the same eNB do not need to provide the same coverage. The CC is compatible with Release 8 or 9 of 3GPP.
In CA, an independent HARQ entity is provided per serving cell in uplink as well as downlink. A transport block is generated per TTI for each serving cell. Each transport block and HARQ retransmission are mapped to a single serving cell.
In the case where CA is configured, a UE has a single RRC connection with a NW. In RRC connection, one serving cell provides NAS mobility information and security input. This cell is referred to as a primary cell (PCell). In downlink, a carrier corresponding to PCell is a downlink primary component carrier (DL PCC). In uplink, a carrier corresponding to PCell is an uplink primary component carrier (UL PCC).
A secondary cell (SCell) is configured to form a serving cell group with a PCell, in accordance with the UE capability. In downlink, a carrier corresponding to SCell is a downlink secondary component carrier (DL SCC). In uplink, a carrier corresponding to SCell is an uplink secondary component carrier (UL SCC).
A serving cell group of one PCell and one or more SCell is configured for one UE.
The above-mentioned LTE Advanced (LTE-A) is studied as a further advanced communication system regarding radio sections in 3GPP (see Non-Patent Documents 7 and 8). The LTE-A is based on the LTE communication system regarding radio sections and is configured by addition of several new techniques thereto. The new techniques include the technique of supporting wider bands (wider bandwidth extension) and the coordinated multiple point transmission and reception (CoMP) technique. The CoMP studied for LTE-A in 3GPP is described in Non-Patent Document 10.
CoMP is the technique of expanding the coverage of high data rates, improving a cell-edge throughput, and increasing a communication system throughput by transmission or reception coordinated among multiple geographically separated points. The CoMPs are grouped into downlink CoMP (DL CoMP) and uplink CoMP (UL CoMP).
In DL CoMP, the PDSCH to one user equipment (UE) is transmitted in cooperation among multiple points. The PDSCH to one UE may be transmitted from one point among multiple points or may be transmitted from points among multiple points. In DL CoMP, a serving cell refers to a single cell that transmits resource allocation over the PDCCH.
Joint processing (JP) and coordinated scheduling (CS)/coordinated beamforming (CB) (hereinafter, also referred to as "CS/CB") are studied as the DL CoMP method.
For JP, data is available at each point in a CoMP cooperating set. JPs are grouped into joint transmission (JT) and dynamic point selection (DPS). DPSs include dynamic cell selection (DCS). In JT, the PDSCH is transmitted from multiple points, specifically, part of or entire CoMP cooperating set, at a time. In DPS, the PDSCH is transmitted from one point in the CoMP cooperating set at a time.
In CS/CB, data is only available in transmission from a serving cell. In CS/CB, user scheduling or beamforming decisions are made with coordination among cells corresponding to the CoMP cooperating set.
Base stations (NB, eNB, HNB, HeNB), remote radio unit (RRU), remote radio equipment (RRE), remote radio head (RRH), relay node (RN), and the like are studied as the units and cells that perform transmission and reception at multiple points. The unit and cell that perform coordinated multiple point transmission are also referred to as a multi-point unit and a multi-point cell, respectively.
3GPP is pursuing specifications standard of Release 12, where the use of small eNBs (cells) is studied to satisfy a tremendous volume of traffic in the future. Examples of the study include the technique of increasing spectral efficiency through installation of a large number of small eNBs (cells) to increase communication capacity.