The present invention provides media sensors for sensing the position of a media in a printer, such as a thermal demand printer. A repositionable media sensor for monitoring the location of a web of label media which utilizes a visible light source projected onto the label media to accurately indicate the position of the media sensor to the operator relative to the label media and facilitate any required adjustment thereof. A printed label sensor is provided for use with a thermal demand printer and includes a light emitter and light detector pair wherein a single light pipe for receiving a sensing beam from the emitter and reflecting the sensing beam at a predetermined angle towards the detector is provided. Preferably, the light pipe is mounted in a peel bar and no electronics are required outside the electronic housing of the printer.

This invention is generally directed to media sensors for a printer.
It is well known in the prior art to provide a thermal barcode printer, operating in a "peel mode", with a take label sensor to detect the presence or absence of an output label. Peel mode is the printer mode which has the printer separating (peeling) a label from a continuous backing and presenting it to the user. The take label sensor is usually located somewhere after the printline. When a label is printed, it is presented, and in some manner activates/de-activates the take label sensor. Only one label is printed at a time. The sensor signal is then used internally by the printer to prohibit printing the next label until the label just printed is removed. The sensor signal may also be used to provide an operator with a visual cue to remove the label. Once the label is removed, the sensor signal changes into its opposite state which cues the printer to allow for the next label to be printed.
Line card or off-the-shelf sensors of a similar type are abundant and used very often where paper handling occurs--copiers, printers, paper shredders, sheet feeders etc. However, most of these sensors are unsuitable for a thermal barcode printer application because they usually have a short sensing capability, or are limited by their mechanical configuration within the application. Thus usually a custom solution is implemented for a thermal barcode printer.
Previously, the most common method of take label sensing in a thermal barcode printer application is as shown in FIG. 47. A detector 14 and an emitter 12 are positioned one above and one below the presented label 22. They are mechanically aligned and usually relatively far apart. The distance required depends upon how easy one wants to load media and ribbon. If they are too close, loading media and ribbon may be difficult. If they are too far, sensor alignment may be a problem. Typical distances are 3-6 inches apart.
When no media is present, the detector 14 senses the emitter's output--the beam 28. When media is present, it breaks the beam (the detector no longer sees the beam). When the presented label 22 is removed, the detector 14 again sees the beam. This difference in sensor signal for beam presence vs. beam absence is the method in which the system detects if a label is present or not.
This "transmissive" method of sensing has the advantage of being less susceptible to media type variations than "reflective" sensing methods because it does not place dependence upon the reflectivity of the media. However, it has disadvantages related to its mechanics. It is more difficult to align the emitter 12 and detector 14 because of the separation distances involved. It also requires electronics outside of the electronics cabinet of the printer which means extra parts including connectors, wire or cable assemblies, mounting brackets and associated hardware. In addition, it presents an obstacle to loading ribbon and media in the printer since the emitter 12 and detector 14 both protrude near the thermal transfer ribbon and media paths. Care must be taken to avoid these obstacles when loading the printer with supplies.
FIG. 48 shows another prior art variation of the transmissive method of take label sensing. It has the emitter 12 and detector 14 mounted inside the electronic enclosure 30 with two light pipes 16, 17 (aligned with the emitter 12 and detector 14, respectively) outside of the enclosure 30 bending the beam 28 at ninety degrees to create a beam 28 perpendicular to the label 22 presented. This method only improves upon the first method by removing the disadvantage of having electronic parts outside of the electronics enclosure 30. The other advantages and disadvantages mentioned above for the transmissive technique remain the same.
Both transmissive methods discussed can have the emitter 12 and detector 14 in either the upper or lower position interchangeably. However, the detector in the upper position makes it less susceptible to ambient light.
FIG. 49 shows yet another prior art method which uses a reflective sensor 11 to determine label presence.
The sensor 11 can be located either above or below the presented label 22. The advantage of this type of sensor 11 is that it may be slightly easier to position in a manner which will not interfere with media or ribbon loading because it is a single contained unit. This method, however, has the disadvantage of being very susceptible to errors due to media variations. It counts on the media to reflect the beam back to the detector. Thus differences in reflectivity of the label in this system can have a profound negative impact on the sensor operation. In addition, label print can cause an additional problem for sensors mounted above the presented label 22. This method typically requires the sensor 11 to be close to the presented label 22 which may still present mounting difficulties. The sensor electronics are again mounted outside of the electronics enclosure, thereby having the disadvantage of additional connectors, wire/cable assemblies, brackets, and associated hardware.
Some type of media sensor is always present on a thermal barcode printer. In general, a media sensor is used to align the printhead means with the label media in order to make sure the labels are printed properly. Other devices that handle labels such as rewinders and applicators may also require a media sensor for sensing the position of the labels that are usually mounted on a continuous backing material, known as a liner or web. The labels are usually positioned on the backing and separated by a small (typically 1/8") gap. For a printer to properly position the print information on the label it must detect the location of this inter-label gap.
The most common way to detect the inter-label gap is to sense the difference in transmissive density of the backing versus the label-backing combination. This type of sensing employs a light source on one side of the print media and a light sensor on the other side of the media. Light emitting diodes are generally used as the light source, and photo transistors are usually used as the sensor.
The media sensor of a thermal bar code printer is normally located somewhere along the media path, before the printhead means. Most printers offer a movable sensor to accommodate a variety of media, because "mark" locations on the media vary. The "mark" is usually the inter-label gap on a roll of media, a notched portion of the media related to the start of the label, or some other indicia or device which can be sensed by the media sensor. These "marks" are easily distinguishable to the user.
Early methods of media sensing had both the emitter and detector movable. Both parts had to be aligned with each other, as well as with the "mark" on the media. A visual marking on each part aided the user to align the sensors. However, because of the "buried" nature of these components (i.e., interference from other printer components and from the media itself), and because of the distances between them and the media, it was difficult to line up the sensor itself, and difficult to line it up with the "mark". FIG. 50 shows a form of this transmissive approach. Since the width and shape of the media may vary, the sensing location must be movable. Also, pre-printed areas on the label can cause variations in the transmissive density of the media. A movable sensor allows avoidance of these areas. The mechanism of FIG. 50 has a movable light source 2 below the media 4, and a movable sensor 6 above the media. The user must make sure that the two are aligned for proper sensing.
In FIG. 51, the lower and upper components 2 and 6, respectively, of the media sensor are linked by a mechanical system. This provides for automatic alignment of the emitter 2 and detector 6, but requires increased complexity and cost. Moreover, this type of prior art media sensor still requires some mechanical work for alignment with the media "mark". And, again because of the distances involved, alignment is still not very precise with this type of system.
Still another variation of the prior art is shown in FIG. 52. The emitter 2 component of the media sensor consists of a number of individual elements which try to provide a uniform source for the media sensor along the entire media 4 width. The detector 6 component alone is movable. The system does not then require that the two sensor elements be aligned mechanically, because it is inherent in the system. The detector 6, however, still needs to be aligned with the media "mark". This again is done with some alignment mark on the sensor housing, which can be blocked by printer components and the media itself making it difficult to align with the media "mark".
It should further be noted that all of the above-described prior art media sensors commonly use infrared light and/or have no visible indicator of the sensing beam itself. In addition, all three of these cases require the media to be passed, or threaded between the emitter and the detector 6. This can make the printer more difficult to load with labels. It also increases the time needed to load the printer and makes misloading more likely.
It is also important to note that if a printer is operating in a thermal transfer mode, a thermal transfer ribbon must be brought into contact with the label as it passes under the printhead means. Since the thermal transfer ribbons are generally opaque, it is important that the media sensor be placed far enough back in the media path to sense the labels before the ribbon is present. This limits the closeness of the sensing point to the print line. Since any variations in the media feed, such as drive roller slippage, that occur between the sensing point and the print line are not detectable, therefore, minimizing this distance is preferable.
Also, some label media types are not detectable using a transmissive technique. These include media which have no inter-label gap, heavily preprinted labels, transparent labels, and labels mounted on opaque backings. In these cases, a black mark is often preprinted on the back of the liner at each label position. The printer must then be outfitted with a second sensor to detect this type of media.


An apparatus for providing improved speech synthesis may include a processor and a memory storing executable instructions. In response to execution of the instructions by the processor, the apparatus may perform at least selecting a real glottal pulse from among one or more stored real glottal pulses based at least in part on a property associated with the real glottal pulse, utilizing the real glottal pulse selected as a basis for generation of an excitation signal, and modifying the excitation signal based on spectral parameters generated by a model to provide synthetic speech.

The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. One area in which there is a demand to increase ease of information transfer relates to the delivery of services to a user of a mobile terminal. The services may be in the form of a particular media or communication application desired by the user, such as a music player, a game player, an electronic book, short messages, email, etc. The services may also be in the form of interactive applications in which the user may respond to a network device in order to perform a task or achieve a goal. The services may be provided from a network server or other network device, or even from the mobile terminal such as, for example, a mobile telephone, a mobile television, a mobile gaming system, etc.
In many applications, it is necessary for the user to receive audio information such as oral feedback or instructions from the network or mobile terminal. An example of such an application may be paying a bill, ordering a program, receiving driving instructions, etc. Furthermore, in some services, such as audio books, for example, the application is based almost entirely on receiving audio information. It is becoming more common for such audio information to be provided by computer generated voices. Accordingly, the user's experience in using such applications will largely depend on the quality and naturalness of the computer generated voice. As a result, much research and development has gone into speech processing techniques in an effort to improve the quality and naturalness of computer generated voices.
Speech processing may generally include applications such as text-to-speech (TTS) conversion, speech coding, voice conversion, language identification, and numerous other like applications. In many speech processing applications, a computer generated voice, or synthetic speech, may be provided. In one particular example, TTS, which is the creation of audible speech from computer readable text, may be employed for speech processing including selection and concatenation of acoustical units. However, such forms of TTS often require very large amounts of stored speech data and are not adaptable to different speakers and/or speaking styles. In an alternative example, a hidden Markov model (HMM) approach may be employed in which smaller amounts of stored data may be employed for use in speech generation. However, current HMM systems often suffer from degraded naturalness in quality. In other words, many may consider that current HMM systems tend to oversimplify signal generation techniques and therefore do not properly mimic natural speech pressure waveforms.
Particularly in mobile environments, increases in memory consumption can directly affect the cost of devices employing such methods. Thus, HMM systems may be preferred in some cases due to the potential for speech synthesis with relatively fewer resource requirements. However, even in non-mobile environments, possible increases in application footprints and memory consumption may not be desirable. Accordingly, it may be desirable to develop an improved speech synthesis mechanism that may, for example, enable the provision of more natural sounding synthetic speech in an efficient manner.

Method, apparatus and computer program product for providing real glottal pulses in HMM-based text-to-speech synthesis


A contact has a leg portion at one end and a resilient contact element at the other end. The resilient contact element is provided with a mother contact nose, on which an external terminal of an electronic part is to be placed, formed on its free end. A child contact nose is loosely engaged with an outer surface of the mother contact nose so that the child contact nose can be idly moved, and the child contact nose has a contacting surface larger than that of the mother contact nose.

1. Field of the Invention
This invention relates to a contact which is to be electrically connected with an external terminal of an electronic part such as IC, etc.
2. Brief Description of the Prior Art
In a socket of IC, etc., a contact, which has on one end thereof a leg portion planted in a socket board and on the other end a resilient contact element bent in a horizontal U-shape and in which the free end of the resilient contact element is provided with a contact nose for placing thereon an external terminal of the IC, and which further has a vertical resiliency, is mostly used.
The contact is formed very thin in correspondence with IC leads arranged in a row at very small pitches, and its contacting area for placing thereon the external terminal is very limited.
When the contact is formed by punching, generation of languishment 3 to the contact nose 2a of the resilient contact element 2, which is to be electrically connected with the IC lead 1, caused by punching is unavoidable as shown in FIG. 1. As a result, as shown by an imaginary line of FIG. 1, when the IC lead 1 is one-sided, there is a fear that no contact is made between the contact nose 2a and the IC lead 1. If the contact is made thick in order to avoid such occurrence, the contact becomes too rigid and an satisfactory resiliency is unobtainable.


A carbon nanotube MEMS assembly comprises a plurality of carbon nanotubes oriented into a patterned frame, the patterned frame defining at least two components of a MEMS device. An interstitial material at least partially binds adjacent carbon nanotubes one to another. At least one component of the frame is fixed and at least one component of the frame is movable relative to the fixed component.

Interest in the use of carbon nanotubes ("CNTs") in engineering applications continues to increase. CNTs are tubes of graphite typically grown from iron nanoparticles or iron, and can be categorized as single-walled nano-tubes ("SWNTs") or multi-walled nanotubes ("MWNTs"). CNTs have many interesting properties, including exhibiting the highest tensile strength and elastic modulus of any known material.
While the behavior of CNTs has been widely studied, the use of CNTs as structural components has proved problematic due to a variety of issues, including the difficulty of manipulating individual CNTs, the difficulty of incorporating CNTs into other structures, and the inherently fragile nature CNTs.

This patent is subject to a terminal disclaimer.


A head drum assembly for a compact-size camcorder such as a digital video camera comprised of a drum cover, stationary and rotating drum, a subcircuit board, a stationary and rotating transformer and a motor stator and rotor. By forming the drum cover, which is attached to the shaft of the rotary drum above the rotary drum, with a conductive material such as an aluminum alloy, the need for a conductive bushing member and earthing plate for the insulating drum cover of the head drum assembly can be omitted, resulting in an overall simpler. As the number of components and manufacturing steps decreases, the manufacturing costs decrease and productivity increases.

1. Field of the Invention
The present invention relates to an improved head drum assembly for use in a tape recorder such as a compact size camcorder of a digital video camera (DVC).
2. Description of the Related Art
Generally, in a tape recorder such as a compact size camcorder of a digital video camera or a video cassette recorder (VCR), in order to scan magnetic tape and thus record video data thereon and/or reproduce video data therefrom, a tape recorder deck includes a head drum assembly having a magnetic head rotatable at high speed.
Referring to FIGS. 1A and 1B, a conventional head drum assembly 100 for a tape recorder includes a rotary drum 110, a stationary drum 120 and a drum cover 130. The rotary drum 110 supports a magnetic head (h), which scans a moving magnetic tape (not shown) to record/reproduce video data thereon/therefrom, and is rotatably mounted on the shaft 140. The stationary drum 120 and the drum cover 130 are press-fitted to be placed on the lower and the upper parts of the shaft 140, respectively, with the rotary drum 110 being interposed therebetween.
The drum cover 130 includes a conductive bushing member 131 in a form of a flange which is press-fitted in the shaft 140 so as to be positioned on the rotary drum 110, a cover member 132 formed by a resin molding and joined with the bushing member 131 by a pair of screws (s), and a conductive earth plate 133 supported by one of the screws (s) to be exposed through the upper surface of the cover member 132 and electrically connected to the sub circuit board 153.
Between the drum cover 130 and the rotary drum 110, a rotary transformer 152 and a stationary transformer 151 facing the rotary transformer 152 are disposed to transmit the signals recorded/reproduced on/from tape by the magnetic head (h). In order to connect the magnetic head (h) and the coil (c) of the rotary transformer 152 through soldering, a terminal 155 is preferably interconnected therebetween as a medium because direct soldering is not easy. Accordingly, in order to enable easy soldering of the coil (c) first, terminal 155 is attached to the lower part of the rotary transformer 152. Next, a hole 115 is defined in the rotary drum 110, and the upper part of the terminal pin 111 is attached to the terminal 115. Next, one end of the coil (c) is soldered to the connecting area between the terminal 155 and the terminal pin 111. As shown in FIG. 2A, the lower end of the terminal pin 111 is soldered to a fine patter coil (FPC) 117 which is disposed at the lower part of the rotary drum 110. Of course, the FPC 117 is connected to the magnetic head (h) by soldering.
To the lower part of the rotary drum 110 is provided a motor rotor 160 which has a donut-shaped magnet 162 disposed within a ring-type rotor casing 161 thereof, and to the upper part of the stationary drum 120, a motor stator 170 is mounted. The motor stator 170 is formed in a type in which the so-called FP coil (fine pattern coil) is formed into a disc pattern and disposed to face the donut-type magnet 162 to obtain a result of a more compact-sized head drum assembly 100. Such motor stator 170 usually has the three-layered structure consisting of first substrate 171, a second substrate 172 and a third substrate 17 which are stacked on one another in turn.
With regard to the motor stator 170, there is a torque generation coil pattern (A) formed on the first and second substrates 171, 172, while a frequency generation coil pattern (B) for speed control and a phase generation coil pattern (C) for phase control is formed on the third substrate 173.
As shown in FIG. 2C, the first substrate 171 is formed of a structure in which a copper membrane 171b in fine pattern is formed on an epoxy substrate 171a, i.e., on a base plate, and a protective layer 171c is formed thereon. The second and the third substrates 172 and 173 are formed in the same structure.
In the head drum assembly 100 constructed as above, the rotary drum 110 is rotated by the electro-magnetic interaction between the motor rotor 160 and the motor stator 170. As the rotary drum 110 is rotated, the magnetic head (h) mounted in the rotary drum 110 is also subsequently rotated, thereby scanning the tape and recording/reproducing data on/from the magnetic tape. The data obtained from the scanning of the magnetic head (h) is transmitted to the rotary transformer 152 and the stationary transformer 151 via the terminal pin 111 and the coil (c), and then to the camcorder system via the sub circuit board 153, which is connected to the stationary transformer 151. The data is then processed at the camcorder system. Reference numerals 140a and 140b denote bearings, and 141 an elastic member, respectively.
However, the conventional head drum assembly 100 constructed as above for use in the tape recorder is accompanied with the following drawbacks:
First, because the cover member 132 is formed of an insulating resin through a molding process, the conductive bushing member 131 and the screws (s) are required to ensure stable electric connection between the sub circuit board 153 and the earth plate 133 for a stable earthing of the head drum assembly 100.
Additionally, because the drum cover 130 requires various components such as the bushing member 131, the cover member 132, the earth plate 133, and a pair of screws (s) to connect the related parts, the number of manufacturing steps such as soldering of the earth plate 133 with respect to the sub circuit board 153, or bonding of the cover member 132 to the bushing member 131, are also increased. As a result, due to increased number of necessary parts and manufacturing steps, productivity deteriorates while the manufacturing costs increase.
Second, a significant amount of components and manufacturing steps are also required in order to connect the magnetic head (h) and the coil (c) of the rotary transformer 152. The terminal 155 has to be attached to, and the hole 115 has to be formed in, the rotary drum 110, so that the upper part of the terminal pin 111, the terminal 155 and the coils (c), can be connected through the hole 115. Then, the lower part of the terminal pin 111 is attached to the FPC 117 which is disposed at the lower part of the rotary drum 110, and the FPC 117 is connected to the magnetic head (h) by soldering.
Furthermore, because signal connection between the rotary transformer 152 and the magnetic head (h) can be achieved only after a plurality of processes, signal transmission rate is degraded, and thus performance of the product deteriorates.
Third, because the motor stator 170 is formed in the three-layered structure having the first substrate 171, the second substrate 172 and the third substrate 173, each of which are bonded to one another in turn, the number of parts and manufacturing steps increase and manufacturing costs increase. Furthermore, the copper patterning on the respective substrates also causes decreased productivity.


A video display control system comprises: a video display having a wide format display ratio; a letterbox detector for sampling video information in pictures represented by input video signals having a letterbox format and generating a control signal for enlarging the pictures for substantially filling the video display means with active video, the letterbox format pictures sometimes having auxiliary information disposed in a border area; and, a circuit for preventing the letterbox detector from sampling the video information in any portion of the border area in which the auxiliary information can be expected to be disposed, when present. In the case of logos, which are generally disposed near or at the right side of the lower border, a horizontal sampling range will exclude the right side of each horizontal line.

1. Field of the Invention
This invention relates to the field of automatic detectors for letterbox video sources, for example as would be useful in wide screen televisions.
2. Description of the Art
In "letterbox" format, an image in wide format display ratio, for example 16.times.9 (also designated 16:9), is displayed across the full width of a narrower format display ratio medium, for example 4.times.3 (also designated 4:3). Movies in a wide format to be broadcast commercially without distortion or cropping are converted by the broadcaster to letterbox format, to enable display on a conventional receiver screen, for example 4.times.3. The broadcaster effectively adds blank or matte top and bottom borders, and broadcasts the combined picture and borders in a 4.times.3 composite image signal. Assuming standard 16.times.9 and 4.times.3 ratios, and standard NTSC signals, only 181 horizontal lines in each field are devoted to the main video, the remaining lines being the matte, gray or black borders. The useful picture information, or main video, is generally referred to as active video, whereas the borders are generally referred to as inactive video, even if the borders are flat fields having some luminance value and/or chrominance component. This distinction and designation is followed herein. The borders may be used, if at all, to display different types of auxiliary information. A first type is generally text, such as storm warnings, news alerts and subtitles. A second type includes station and network logos, which are often graphic or a combination of text and graphics. Both types of auxiliary information might be present together, or separately. Both types of auxiliary information are also generally referred to as active video.
When such letterbox displays (in 4.times.3 format) are shown on a wide screen television, for example 16.times.9 format, the video signal can be vertically zoomed, that is enlarged, by a factor which both increases the portion of active video to substantially fill the wide screen display, and at the same time, substantially eliminates the upper and lower borders. This can be accomplished without incurring image aspect ratio distortion. It is a useful feature to automatically detect letterbox sources and vertically enlarge the active portion of the video source signal so as to substantially fill the display screen.
An automatic letterbox detector in a wide screen television is disclosed in PCT/US91/03739 (WO 91/19390). As described therein, the uppermost and lowermost active video areas are detected by calculating two gradients for each line in the video field. Four values are required to calculate the two gradients: maximum and minimum values of the current line, and maximum and minimum values of the previous line. The first gradient, designated the positive gradient, is formed by subtracting the minimum value of the previous line from the maximum value of the current line. The second gradient, designated the negative gradient, is formed by subtracting the minimum value of the current line from the maximum value of the previous line. Either of the gradients may have positive or negative values depending on scene content, but the negative values of both gradients may be ignored. This is because only one gradient may be negative at a time, and the magnitude of the gradient with the positive value will always be greater than or equal to the magnitude of the gradient with the negative value. This simplifies the circuitry by eliminating the need to calculate an absolute value of the gradients. If either gradient has a positive value which exceeds a programmable threshold, video is considered to be present on either the current line or on the previous line.
These values can be used by a microprocessor to make a determination of whether or not the video source is in the letterbox format and to determine the first and last line numbers of active video. The calculation can be performed only for the top (or the bottom) of the image, provided means are provided for centering the image vertically. Inasmuch as the detection of active video is a function of gradient rather than luma absolute value, the device can detect inactive borders of a predetermined matte color, provided the borders have a substantial (but unchanging) luminance level. The luminance level detector is enabled for only about 70% of each line in order to improve signal to noise ratios.
However, if the borders are used to display auxiliary material, such as storm warnings, news alerts, subtitles, station or network logos, and the like, the automatic letterbox detector will return operation to the standard, non-zoomed operation. This may be desirable for storm warnings, news alerts and subtitles, but can be a significant nuisance for logos. Moreover, continuous transmission of a logo in the border area of a letterbox source can prevent automatic detection of the source as being letterbox in the first instance.


Systems and methods are provided for managing multiple wireless links, e.g., between base stations and wireless headsets. Each wireless link communicates data packets (e.g., audio data packets) according to a wireless protocol (e.g., Bluetooth) defining a series of connection intervals having a defined number of frames (e.g., Bluetooth eSCO intervals including 6 or 12 frames per interval). A controller stores interval segmentation data specifying a first interval segment (including a first subset of frames) allocated to original transmissions of packets and at least one additional interval segment (including additional subsets of frames) allocated to retransmissions of failed packets. The controller uses the interval segmentation data to manage timing for packet transmissions and retransmissions by the various wireless devices, such that each device (a) sends transmissions only during the first interval segment and (b) sends retransmissions only during the additional interval segment(s), to thereby reduce interference between the various wireless links.

Enterprise wireless communications environments, e.g., call centers, often use Bluetooth Classic, Bluetooth derivatives such as Bluetooth Low Energy (BLE), Digital European Cordless Telecommunications (DECT), and other packet-based radio systems for wireless communications. In such environments, user density and effective wireless range for wireless communications (e.g., voice, streaming music, etc.) are important factors defining the capability or quality of the respective environment.
User density relates to the number of active users in a restricted area that experience an acceptable service level, e.g., according to defined performance standards. User density typically depends on several parameters such as the traffic load per link, the number carriers to hop over, the link capacity needed per user, and the robustness of the link protocol. The effective range of a wireless communications system typically depends on noise conditions in the receiver and the implemented modulation scheme. For example, wide-band, high-rate modulation schemes are typically more susceptible to noise and result in a lower range.
In a Bluetooth system, voice is compressed and sent in a series of short packets to the receiver, according to a frequency-hopping and time-slotted protocol. A packet may be interfered by packets from other Bluetooth transmitters, or by signals from other transmitters in the 2.4 GHz ISM band used by Bluetooth. A major source of interference in which band is WiFi technology based on the IEEE 802.11 standard. A packet reception may be interfered by another packet when there is a collision in time and in frequency. Whether a packet is lost (e.g., received erroneously at the intended recipient) depends on (1) the strength of the interference power with respect to the strength of the intended received power, (2) whether the packets (partly) overlap in time, and (3) whether the packets make use of the same (or near-adjacent) carrier frequency. An erroneously received packet (e.g., where at least one bit in the received bit pattern is erroneous) is referred to herein as a "failed packet," whereas a received packet containing the true content is referred to herein a "successful packet." The "true content" of a packet refers to the content (i.e., bit pattern) of the packet transmitted by the transmitting device for receipt by the recipient.
The quality of a Bluetooth connection (or other packet-based radio connection) may be defined by an error rate experienced at the wireless receiver, referred to herein as the Data Error Rate (DER), which may define, for example, a Bit Error Rate (BER), a Packet Error Rate (PER), or a Frame Error Rate (FER) experienced at the Bluetooth receiver. Voice over Bluetooth is quite robust and an acceptable quality (expressed in Mean Opinion Score, or MOS) is achieved at an FER of 1% and below.
As noted above, Bluetooth uses a frequency-hopping and time-slotted protocol. Mutual interference occurs when different users overlap both in frequency and time. Several methods have been investigated to improve user density in Bluetooth environments, for example by reducing the transmitted interference or by improving the robustness of the receiver, e.g., to reduce the impact of packet collisions, and thus failed packets, at the receiver. Reduced interference can be achieved by lowering the duty cycle of the transmission, for example by using lower-rate audio codecs like the 32 kb/s CELT codec, increasing the voice packet interval, or "connection interval" TeSCO from 7.5 ms to 15 ms, or applying Discontinuous Transmission (DTX). The robustness of the receiver can be increases by increasing the maximum number of retransmission opportunities (as discussed below), or by applying error concealment techniques that permit higher frame erasure rates (FER). Some improvement measures require hardware changes (typically carried out by the chip manufacturers), others can be implemented with software changes only.
One particular technique for reducing transmission errors and thus increasing user density involves automatically retransmitting failed packets. For example, some existing Bluetooth systems are configured to perform one or more "fast retransmission" of each failed packet to reduce transmission errors. In a fast packet retransmission (ARQ) scheme, each received packet is checked for errors (using the Cyclic Redundancy Check CRC that is appended to each packet), and if errors are detected in the received packet, a request for retransmission is returned, leading to a retransmission of the same packet directly in the next available slot. The retransmitted packet is checked for errors and if the CRC check fails again, a new retransmission requested, and so on. However, these packet retransmissions may again result in collisions, even with retransmissions on links that gave rise to the earlier errors caused by repeated interference.
FIG. 1 illustrates a timing diagram of a mono voice link (eSCO) between a wireless headset and base station for a single user, according to a standard Bluetooth protocol that implements fast packet retransmission (ARQ) for failed packets. Each device (wireless headset and base station) includes is configured to transmit data to and receive data from the other device. One device (e.g., the base station) may act as the master device ("master"), with the other (e.g., the headset) acting as a slave device ("slave"). Each device (e.g., master and slave) analyzes each packet received from the other device using a Cyclic Redundancy Check ("CRC check") to determine whether the received packet contains the true content (i.e., a successful packet) or contains erroneous data (i.e., a failed packet). If the CRC check passes, the receiver notifies the transmitter of the passed CRC check, and the transmitter does not retransmit the packet. However, if the CRC check fails, the receiver notifies the transmitter of the failed CRC check; if the transmitter does not receive a notification of the CRC check within a certain time period, this may automatically be interpreted as a failed CRC. A failed CRC check prompts to the transmitter to retransmit the failed packet until either (a) the receiver notifies the transmitter of a passed CRC check after a particular retransmission of the packet (indicating a successful packet) or (b) the transmitter reaches a predefined maximum number of retransmissions.
Thus, with reference to the mono voice link shown in FIG. 1, the master performs an initial transmission of a first voice packet to the slave, followed by the slave performing an initial transmission of a second voice packet to the master, along with a result of a CRC check performed by the slave indicating whether the first voice packet from the master was received at the slave as a successful packet or as a failed packet. If the CRC check result indicates a failed CRC check, the master initiates a first retransmission of the first voice packet, along with a result of a CRC check performed by the master indicating whether the second voice packet from the slave was a successful packet or a failed packet. Retransmissions by the master and/or slave may continue until the master and slave each receive a confirmation of a successful packet reception from the other device, or until a maximum number of retransmissions is reached.
FIG. 1 also indicates the carrier frequency fx of each respective transmission. As indicated, each retransmission may be performed on a different carrier frequency. This pattern is repeated during each connection interval TeSCO, each time using different carrier frequencies. The connection interval TeSCO may be 7.5 ms or 15 ms, e.g., depending on the implemented codes.
In the Bluetooth standard, the maximum number of retransmissions in each connection interval by each device (master and slave) can be negotiated for each link via a link manager (LM) protocol during a link setup. In many systems or configurations, the maximum number of retransmissions is set at two, such that any particular packet can be sent up to three times (original transmission plus up to two retransmissions). In systems or other configurations, the maximum retransmission number is increased to three, which has been found to increase the allowable user density by about a factor of 1.4×.
FIG. 2 shows an example timing diagram of a mono voice link (eSCO) according to the Bluetooth protocol shown in FIG. 1, for three users A, B, and C in physical proximity to each other, e.g., three headset users in a call center. The voice link for each user comprises a Bluetooth link between a base station (indicated at TX) and headset (indicated at RX). As discussed above, for each mono voice link, a voice packet is first sent from master (base station) to slave (headset), followed by a voice packet sent from slave (headset) to master (base station). Both packets are sent on the same carrier frequency fx. After the first transmission (indicated by dark shaded boxes in FIG. 2), there are two retransmit opportunities (indicated by lightly shaded boxes in FIG. 2), which may be sent on different carrier frequencies, e.g., according to a pseudo-random frequency-hopping scheme. This pattern is repeated during each connection interval TeSCO, each time on different carrier frequencies. As discussed above regarding FIG. 1, each packet received by each respective device is checked for errors using a CRC code, and retransmission(s) are requested until the packet is successfully received or the maximum number of retransmissions (e.g., 2 or 3) has been reached.
In conventional systems, the connections of the different users A, B, and C are not synchronized in time, and thus transmissions and retransmissions of the different users may overlap in time, potentially interfering with each other. For example, as shown in FIG. 2, the transmissions of user B (partly) overlap with the transmissions of user A. Both the first transmissions (dark shaded boxes), and also the possible retransmissions (light shaded boxes) of users A and B overlap in time. Thus, after a transmission of user A collides with a transmission of user B, the retransmission(s) of user A may collide with retransmission(s) of user B (at least in instances of frequency overlap between users A and B). Further, the first transmission of user C may interfere with retransmissions of users A and B, and retransmissions of user C may interfere with further retransmission of users A and B. The collisions between packets of users A, B, and C trigger even more retransmissions, further increasing the overall traffic load.

Systems and methods for managing wireless packet communications by assigning separate resources for sequential transmission attempts


The present invention relates to a modular erogenous stimulation system including at least one vibratory device for stimulating the erogenous zones and at least one control module that for controlling the operation of the vibratory device; and to an embodiment of the at least one vibratory apparatus that may be worn by a female for stimulating the internal vaginal erogenous zones, the external clitoral erogenous zones, or both the internal and external clitoral erogenous zones of the female genitalia simultaneously, while allowing sufficient clearance of the vaginal canal to also permit insertion of a penis or other similarly configured and dimensioned implement, such as a dildo or vibrator, when the apparatus is being properly worn by the female to create an interaction between the partners that is pleasurable for all involved.

Many sexual stimulation devices are presently available for use by both men or women with or without a partner. These devices can be strictly manual or may include a vibrating mechanism, and may be used either internally to stimulate the vagina and G-spot, or externally to stimulate the clitoris, and may also provide penial or anal stimulation depending upon their design and dimensions. Some such devices have drawbacks, which embodiments of the massager illustratively described herein can overcome.
For example, the selection of erogenous stimulation devices presently available lack both upgradeability and interoperability that would allow a purchaser to enter the market for such stimulators at a reasonable price and then upgrade the functionality and expand their collection of devices over time without sacrificing the initial investment, due to the ability to interchange the modular components and capitalize on their cross-functionality.

Systems, devices and methods for personal massage


The present invention relates to a high-heat-delivery device suitable for use in an hair straightener, a hair curling iron or an ironing apparatus and suitable for heat transfer to a substrate by direct contact with said substrate, comprising at least one element (A) having a heat transfer contact surface area and at least one element (B) having a heat transfer contact surface, wherein the element (A) comprises a thermoconductive thermoplastic polymer composition comprising at least one polymer and a thermoconductive additive and wherein element (B) comprises a thermoplastic polymer composition comprising a polymer and at least one thermo-releasable substance. Further, the present invention relates to a method for releasing a thermo-releasable substance. Furthermore, the present invention relates to an ironing apparatus, a hair straightener and a hair curling iron comprising the high-heat delivery device.

An efficient heat transfer to a substrate is difficult to carry out. Suitable heating may require very high temperatures if the heat transfer is not efficient enough. Most heating apparatuses comprise a heated metallic plate brought into contact with a substrate to be heated.
Transferring heat onto a substrate can damage the substrate. In particular, contacting a substrate at high temperatures, such as temperatures above 150° C. can cause burns to the substrate. A particular example is the application of hair straighteners, wherein hair to be straightened is submitted to high temperatures and result in substantial damaging of the hair, such as scorching, split ends, breakage, sharp bends, etc.
U.S. Pat. No. 6,622,735 describes a hair iron comprising a hair heating surface and a pressing surface of an iron covered with iron press covers made from a woven or nonwoven cloth of heat-resistant synthetic fibers.
US 2008/0041408 recites a hair styling apparatus that has a heating member and a polytetrafluoroethylene cloth covering the heating member.
It is thus an object of the present invention to provide a high-heat delivery device which efficiently transfers heat at temperatures equal to or above 150° C. to a substrate while causing less damage to the substrate.
The object is met by the high-heat-delivery device suitable for heat transfer to a substrate by direct contact with said substrate, comprising at least one first element (A) having a heat transfer contact surface area, wherein the first element (A) comprises, or is made of, a thermoconductive thermoplastic polymer composition comprising at least one polymer and a thermoconductive additive. The device according to the present invention achieves the aim of efficiently providing the required heat to a substrate while causing less damage to said substrate.
In an embodiment of the present invention, the device further comprises at least one element (B) having a heat transfer contact surface area, the element (B) comprising a polymer composition comprising at least one polymer and at least one thermo-releasable substance. In this embodiment, an element (B) together with element (A) of the device, allows the release of a substance onto, or into, the substrate. The release of the thermo-releasable substance is carried out with the heating of element (B). The term 'thermo-releasable' is to be understood as the release of a substance under the effect of heat.


Nonlinear image filter defined by local edge intensity and slope and is useful noise and artifact removal during image processing; applications include digital still cameras and video cameras.

The invention relates to image processing, and more particularly to image filtering methods and related devices such as digital and video cameras.
There has been considerable growth in the sale and use of digital cameras, both still and video, in recent years. FIG. 4 is a block diagram of a typical digital still camera which includes various image processing components, collectively referred to as an image pipeline. Color filter array (CFA) interpolation, gamma correction, white balancing, color space conversion, and JPEG (or MPEG for video) compression-decompression constitute some of the key image pipeline processes. The typical color CCD consists of a rectangular array of photosites (pixels) with each photosite covered by a color filter: e.g., red, green, or blue. Thus to recover a full-color image (all three colors at each pixel), a method is required to calculate or interpolate values of the missing colors at a pixel from the colors of its neighboring pixels. Such methods lead to artifacts in the full color image which should be removed by filtering.
Similarly, high-frequency elements of video images are commonly eliminated using conventional linear filters. However, the size of such filters becomes large when the desired characteristics are demanding, and this results in prohibitively large circuit size.
Infinite impulse response (IIR) filtering is often used in acoustical signal processing. However, it is little used in image processing due to its side effects, which are often imperceptible in sound but apparent in images.
Filtering using the matching method compares input signals with a stored database and outputs appropriate signals. Although this method works well in some situations, the output quality can be low if the database does not match the input. Also, this method consumes large amounts of memory and computational power.


An in-axle shaft speed sensor has an annular configuration and is attached to the axle differential bearing adjustment ring. An annular sensor housing ring has a radially inwardly extending flange with inwardly cantilevered tabs formed therein for absorbing by localized axial deflection the clamping loads of attachment screws. The stator ring is configured for an axial air flux gap with the rotor poles and is axially adjacent the housing ring and has cut-outs therein to permit free deflection of the tabs and prevents axial distortion of the stator ring and mis-alignment of the poles.

The present invention relates to an in-axle rotational speed sensor assembly for mounting to a fixed or stationary ferromagnetic member such as a drive axle differential bearing adjustor having a central opening therethrough for receipt of a rotatable member such as a shaft for measurement of the rotational speed thereof. Wheel speed sensors have become increasingly important for providing an electric signal indicative of wheel speed for use with anti-lock brake systems (ABS), traction control, and differential lock-up systems in brake control systems, and the like. Typically, the sensor provides a wheel speed signal to a micro-processor-based control unit (ECU) as is well known in the art. Examples of such systems and/or sensors may be seen by reference to U.S. Pat. Nos. Re. 30,522; 3,961,215; 3,929,382; 3,556,610; 3,604,760; 4,585,280; 4,361,060; 3,768,840; 4,818,035; and 4,863,221, disclosures of which are incorporated herein by reference.
Typically, such rotational speed sensor assemblies are electromagnetic in nature, and rely on alignment of rotor teeth or spaces between rotor teeth rotating past the sensor to complete or break, respectively, the magnetic flux path to produce a digital or analogue signal indicative of the rotational speed of the motor.
Placement of wheel speed sensor assemblies within the axle (i.e., "in-axle") to protect same is also known, as may be seen by reference to U.S. Pat. Nos. 3,769,533; 4,724,935; 4,836,616; 4,862,025; and 4,862,028; disclosures of which are incorporated herein by reference.
Annular rotational speed sensor assemblies having an annular toothed stator/sensor surrounding a rotating toothed rotor, or vice-versa, are well known in the art. Annular speed sensor assemblies are preferred over single or multiple point type sensor assemblies in certain situations, as they provide a relatively high signal-to-noise ratio, tend to be self-compensating for run-out errors between the rotor and stator, and require little or no adjustment. Examples of such in-axle annular speed sensor assemblies may be seen by reference to U.S. Pat. Nos. 4,870,911; 4,027,753; and 4,689,557, the disclosures of which are incorporated herein by reference.
The annular speed sensor described in the above-referenced parent applications have provided for a low-cost sensor especially for use with drive axles at an inboard location where the sensor could easily be protected. However, some problems have been encountered in assembly in which certain parts of the sensor were deformed during mounting, and affected the signal output of the sensor; and, thus it has been desired to provide such an in-axle wheel sensor which can be easily and reliably assembled into the drive axle without requiring special tools or measurements during the assembly, and which is not distorted during assembly so as to affect the signal output.


A system and method for predicting the location of a vehicle in an electronic toll collection system employing a wide area communication protocol. The vehicle includes a transponder that sends reports regarding the position of the vehicle and the time at which the position was determined. The system includes a vehicle position predictor for estimating the future position of the vehicle within a roadway based on two or more reports of past positions and the times at which they were recorded. Speed data or other data impacting likely future position may also be reported and factored into the estimate. The estimate of future position may be used in connection with triggering enforcement measures, timing a toll transaction, integrating wide area toll communications into a legacy toll transaction system, or for other applications.

In Electronic Toll Collection (ETC) systems, Automatic Vehicle Identification (AVI) is achieved by the use of Radio Frequency ("RF") communications between roadside readers and transponders within vehicles. Each reader continuously emits a coded identification signal and when a transponder enters into communication range and detects the reader the units transact information, in particular the unique identity of the transponder. In the USA, current AVI RF communication systems are licensed under the category of Location and Monitoring Systems (LMS) through the provisions of the Code of Federal Regulations (CFR) Title 47 Part 90 Subpart M.
The reader is typically connected to another controller, herein referred to as a Roadside Controller, which is also connected to a vehicle detector and an imaging system which work in association with the AVI RF system to permit all vehicles passing through the toll coverage to be detected, classified, and identified in order to permit the operator of the ETC system to apply appropriate charges to the owner of the vehicle. Those vehicles not equipped with transponders are typically photographed and the license plate numbers are analyzed to identify the vehicle. In ETC systems, it is generally necessary to determine in which lateral position a vehicle is traveling when it reaches the point of toll. For example, it is often necessary to separate vehicles equipped with transponders from vehicles without transponders and associate video images with vehicles that are not equipped. In other systems, the lanes may be equipped with physical barriers that will only be opened on valid transponder identification for the specific lanes. In order to do so in any of these systems, the ETC system must clearly identify where the subject vehicle is located within the multiple zones of coverage of the system.
Current ETC systems can be classed as either lane-based or open-road.
In a lane-based system, the reader controls reader channels, each of which corresponds to RF coverage of an individual vehicle lane, which will then communicate with vehicles in individual lanes. The RF communication coverage area of each channel is often referred to as the capture zone. In a lane-based system the capture zone is typically 1.2 to 2.4 meters (4-8 feet) long and 3 meters (10 feet) wide. Lane-based systems also require that the vehicles be laterally constrained to the lanes through appropriate physical measures such as barriers between lanes. Thus when a vehicle with a transponder passes through a capture zone, the vehicle location is easily associated with the specific lane at that instant in time, and the short length of the zone allows for accurate timing alignment with the vehicle detection imaging systems.
Open-road systems in contrast allow traffic to free flow without impediment of lane barriers. Thus vehicles may be laterally located anywhere over multiple lanes of traffic, for example they can be mid-way between two lanes, and moreover need not be traveling parallel to the lanes, for example they can be changing lanes as they pass through the toll area.
Current open-road toll ETC systems can be classed either as open-lane-based or locator-based.
Open-lane-based systems employ RF capture zones similar in size to the lane-based systems but the systems employ more channels than lanes to provide overlapping or staggered RF capture zones over multiple lanes. The reader analyses detections from multiple capture zones to determine to which zone to assign the vehicle location. An example open-lane-based ETC system in described in U.S. Pat. No. 6,219,613, which is owned in common herewith.
Locator-based systems in contrast use wide-area communications, where a single RF channel spans multiple traffic lanes in width and is also much longer than a lane-based system. The capture zone of locator-based systems is typically 16.8 meters (55 feet) wide by 36.6 meters (120 feet) long. One major difference is that, unlike the lane-based approaches, multiple transponders can be simultaneously present in the coverage area. The locator-based system typically uses two receivers, each with a separate antenna, to simultaneously receive signals from a transponder. By comparison of the properties of the signal received at the two receivers, such as amplitude difference, phase difference or time difference of arrival, and knowledge of the RF communication timing, the system can determine the vehicle location to a precision equal to that to the lane-based systems. The locator antenna system may operate in accord with the system described in U.S. Pat. No. 6,025,799, which is owned in common herewith.
One issue for ETC systems is synchronizing the RF communication system and the vehicle detection system. If the communication occurs too early or too late, then it is possible to wrongly associate another vehicle with the communicating transponder. Additionally, vehicle positions relative to the lanes can be changing as vehicles pass through the toll area, so that it is necessary that a communication occurs with the moving vehicle while the car is close to the vehicle detection point. At 70 mph (102 feet per second) a vehicle will typically only remain in the lane-based capture zone for less than 60 ms while in a locator-based system this time increases to around 1200 ms. It is noted that a toll transaction may require multiple information packets to be exchanged between the reader and the transponder, and this must occur during that short time.
To ensure this synchronization, current North American toll systems employ Time Division Multiple Access (TDMA) RF communications at nominally 900 MHz. Each information packet exchange—transmission of data and its acknowledgement—occurs over a period of a few milliseconds. The TDMA structure allows the reader to interrogate specific transponders at time instants controlled by the reader, thereby allowing the reader to synchronize the data exchange with the transponder with the timing of the other roadside equipment.
The potential exists to perform the RF communications with a non-TDMA, more general purpose wide area communication system. In particular, in the US, the CFR 47 provisions allow for vehicular and roadside communications under Parts 90 and 95 in the category Dedicated Short Range Communications (DSRC) Service at nominally 5.9 GHz using an extension of the IEEE 802.11 communication standard as specified currently under ASTM E2213. However, unlike LMS, DSRC communications permitted are not restricted to location and monitoring functions and can extend up to 400 m or more in range from the communication antenna.
The DSRC communication system is intended for sharing for multiple applications and, while 802.11 based communication systems support high data rates, there are inherent latencies in the communications and variable communications delays.
It would be advantageous to provide for an ETC system and method capable of vehicle detection employing a wide area communications protocol, in particular one with variable communication delays

Real-time vehicle position determination using communications with variable latency


An arrangement, a system and a method distribute messages in a communication system supporting communication of packet data. The arrangement includes a number of processors communicating with each other. Each processor is connected to all other processors via at least two physically separate networks. For each processor, information holding devices are provided for keeping information about all communication paths to all other processors. For obtaining information, first messages are sent from each processor to all other processors using all of the at least two networks.

The present invention relates to a distributing arrangement for distribution of messages in a communication system supporting communication of packet data. The invention also relates to a communication system including a number of distributing nodes each of which includes a number of processing means. The invention also relates to a method of fault tolerant communication of messages in a communication system supporting communication of packet data. Particularly the invention relates to an arrangement and a system respectively for fault tolerant communication of messages.
In data/telecommunication systems messages are sent between different processing means. It has become common to implement LAN (Local Area Network) technology within data- and telecommunication equipment. Two reasons therefore are that the LAN technology has become attractive since it is cost effective and that the LAN technology furthermore provides a good performance. However, to provide a satisfactory operation of the systems, the communication needs to be as fault tolerant as possible to introduce reliability, redundancy and freedom from single point failures. A single LAN segment is not sufficiently reliable since the central equipment is not redundantly implemented. In known systems so called FDDI/DAS (Fiber Distributed Data Interface/Dual Attach Station) solutions or alternatively high availability ATM (Asynchronous Transfer Mode) solutions are therefore used.
Both FDDI/DAS and ATM solutions are however expensive.
An implementation of a FDDI/DAS ring is for example known. In that case redundancy is provided for through connecting each processing means to the dual ring and the handling of faults is taken care of in the points of connection.
FDDI/DAS technology is expensive and furthermore it is limited to 100 Mbps making topology restraints on nodes which require a higher bandwidth necessary. Thus, in that case the costs are still further increased since more network interfaces are needed. Furthermore the degree of freedom in software configuration is somewhat limited.
Alternatively a high availability ATM (Asynchronous Transfer Mode) switch with built-in reducancy may be used. Such a solution is however even more expensive than the FDDI/DAS solution. In some technologies the fault tolerancy is handled by protocols on a high level or on the routing level. Furthermore, through the implementation of bridges between the different networks or network segments, fault tolerant communication is not provided everywhere and the communication with some processing means may be lost if a bridge is broken.
What is needed is therefore an arrangement through which fault tolerant communication can be offered in a data/telecommunication system supporting communication of packet data. Still further an arrangement is needed through which fault tolerant communication can be provided and through which the amount of messages sent within the network, i.e. the network overhead produced hereby, can be kept low. Particularly an arrangement is needed through which it is possible to detect errors in equipment as well as on communication paths and through which it is possible to detect when a communication path etc. functions satisfactorily again and through which messages can be sent from one processing means to another with a high degree of availability, i.e. with a high probability of success. Still further an arrangement is needed through which faults can be detected in a fast and efficient manner thus enabling restoration of errors.
Particularly an arrangement is needed through which the provision of fault tolerance is transparent for high level protocols and on the routing level. Still further an arrangement is needed which allows the use of standard components (hardware). Particularly an arrangement is needed which is cheap and which has a high performance and which is reliable, shows a high degree of redundancy and which provides freedom from single point failures. Still further an arrangement is needed which enables an automatic error detection and failover as well as automatic recovery. Particularly an arrangement is needed which enables operator notification of failures particularly while the operation still is substantially unaffected.
Particularly a distributing arrangement for distribution of messages in a communication system is needed which meets the above mentioned requirements. Still further a communication system supporting communication of packet data is needed through which the above mentioned objects are achieved.
Further yet a method providing fault tolerant communication in a communication system supporting communication of packet data is needed through which the above mentioned objects are achieved.
Therefore a distributing arrangement for distribution of messages in a communication system is provided which comprises a number of processing means which communicate with each other through sending of messages. Each processing means is connected to all the other processing means via at least two communication networks or network segments which are physically separated from each other. For each processing means information holding means are provided for keeping information about all communication paths to all other processing means and this information is obtainable by way of sending first messages, particularly with a given frequency, from each processing means to all the other processing means using all of said at least two communication networks. Such first messages may be sent separately but they may also be piggy-backed on e.g. ordinary traffic messages, or a combination of both. Advantage may also be taken of information indirectly obtainable through the ordinary traffic that flows.
In an exemplary embodiment a predetermined time interval is given for each processing means and first information messages sent from one processing means substantially simultaneously to another processing means using at least two physically separated communication paths including different networks should arrive within the predetermined time interval. If they do so, the at least two different communication paths using different communication networks both function. In an advantageous embodiment the first information messages are special purpose broadcast messages and preferably each processing means send their respective special purpose broadcast messages on all networks or network segments substantially simultaneously. Alternatively the first messages consist of a burst of unicast messages. Particularly each processing means comprises means for detecting anomalies or asymmetries in the reception of such first messages from one and the same sending processing means and when such an asymmetry or anomaly is detected, the receiving processing means enters a decision process to localize the error and or to establish the kind of the error. In a particular embodiment means are provided for comparing the reception of first messages during a first time interval and the reception of first messages during a subsequent observation time intervals. If an anomaly or an asymmetry in the reception during the first observation time interval still remains in the subsequent observation time interval, the receiving processing means sends a second message, e.g. a unicast message containing information about an error or about the result of the sending of the first messages, to the sending processing means on all communication networks/network segments. In an alternative embodiment a second message, e.g. a unicast message, is sent to the sending processing means on all networks/network segments as soon as an error is detected. Still further, more than two observation periods during which one and the same anomaly remains could be the requirement for sending out a second, e.g. a unicast message containing an error announcement. With an asymmetry or anomaly is meant that not all first messages from one and the same sending processing means arrive within the time window of the receiving processing means. It is supposed that each processing means knows which first messages that should be received. Actually it is sufficient to know the number of networks.
For each processing means there may of course be several parallell fault detection processes run at the same time towards different other processing means due to working within the time window and since all processing means communicate with all other processing means.
Particularly, if no messages at all are received in a receiving processing means over one of the networks, said processing means provides for transmission of a broadcast message which is broadcasted to all other processing means using said at least two networks (all available networks) to inform said other processing means that no messages whatsoever are received on that particular network.
In a particular embodiment each processing means comprises means for generation of an alarm message if an anomaly or an asymmetry remains for a given number of observation time periods, which alarm message then is sent to an operation system managing the distributing arrangement using all (available) of said at least two networks.
Instead of using a time window to detect anomalies the messages can be numbered in an appropriate manner, e.g. in sequence, and then can be detected when a message numbered in a particular way is only received e.g. over one network or if it is completely missing etc. since a packet numbered in the same way should be received on all interfaces.
Particularly, in each processing means a table is dynamically built using received unicast messages and possibly information in received broadcast messages (if the network(s) support(s) a broadcasting functionality), which information is used to control the sending of messages from the respective processing means. In a particular embodiment each processing means keeps information about the existence of all other processing means. Particularly said tables contain information about all usable communication paths to all peers, i.e. all other processing means, with which the respective processing means communicate.
In an alternative embodiment each processing means comprises means for sending response messages with information about received first messages, e.g. special purpose broadcast messages, at least to the respective sending processing means. Particularly the information about received first messages is provided in unicast special purpose messages which are sent to the respective sending processing means and they include information about on which network(s) first message(s) is/are received. Said response unicast special purpose messages are sent on all (available) of said at least two networks substantially simultaneously. In a particular embodiment said response messages are used to dynamically build a table in information holding means provided for each processing means which information is used to control the sending of messages from the respective processing means. Particularly said table shows all usable communication paths to all peers, i.e. all processing means, with which a respective processing means communicate.
In particular embodiments an intermediate message handling device is connected to each processing means (or some of the processing means) respectively for handling the sending of said first messages and second messages. In the embodiment implementing sending of response messages, said intermediate devices handle the first messages and response messages.
In a particular embodiment an intermediate message handling arrangement is provided containing all (or a number of) the intermediate message handling devices. In an alternative embodiment means are provided in each (or some of the) processing means for handling the generation/sending/receiving of first and second messages or first messages and response messages.
In a particular implementation the information provided in the information holding means is also used for controlling the sending of messages so as to share the load between the communication paths in an appropriate manner.
In one embodiment the at least two networks comprise separate networks such as different local area networks or networks based on different technologies. There may be more than two networks. Of course also networks based on one and the same technology may be used. In a particular advantageous embodiment the networks support a broadcasting functionality. Alternatively some network(s) support(s) a broadcasting functionality whereas one or more other network(s) do not.
Therefore also a communication system supporting packet data communication is provided which includes a number of distributing nodes for distribution of messages. Each node comprises a number of processing means communicating with each other. All processing means communicate via at least two different networks or network segments which networks/network segments are physically separated. Each processing means comprises or is associated with means for sending first information messages to all other processing means which messages are sent on each of said at least two networks. For each proccessing means information holding means are provided in which the information resulting from the sending of said first information messages is collected to provide information about the available communication paths to all other processing means respectively.
Examples on nodes in which the inventive concept can be implemented are the SGSN (Serving GPRS Support Node) and the GGSN (Gateway GPRS Support Node) wherein GPRS (General Packet Radio Service) is the packet data service of GSM, c.f. e.g. GSM 03.60 V5, 2.0, 1997-12 and the P-MSC of PPDC which is the packet data service of PDC (Pacific Digital Communications).
In a particularly advantageous embodiment the first information messages consist of special purpose broadcast messages and in each processing means detecting means are provided for detecting if first information messages sent from particular sending processing means using the at least two separate networks arrive within a predetermined time interval as well as means of sending a special purpose unicast message to a sending processing means in case messages are not received on all networks within the predetermined time interval for a given number of observation time intervals, to indicate the result or that one of the communication paths contains an error. Particularly, if a processing means does not receive any message on a particular network at all, information thereon is provided in its own next first information broadcast message which is provided to all other processing means using all available networks.
Alternatively the first messages are a burst of unicast messages, e.g. in case a network does not support broadcasting. In an alternative embodiment each processing means comprises means for sending response messages to sending processing means upon reception of first information messages from said sending processing means. Particularly said response messages comprise unicast response messages including information about over which network(s) first information messages is/are received. Particularly each processing means comprises or is connected to information holding means in which a table is built using the information received in second information messages (unicast special purpose messages) or response messages so as to dynamically provide for updated information about available communication paths to all other processing means.
In a particular embodiment message handling means (intermediate devices) responsible for the sending/receiving of first messages and second messages or response messages are provided in connection to one or more (or all) processing means and form an intermediate arrangement comprising one intermediate device connected to each processing means. In an alternative embodiment the message handling means for handling the sending/receiving and generation of first messages and second messages or response message are comprised in the respective processing means.
The at least two networks may be networks of the same kind, or of different kinds and there may be two, three or more different networks. Examples on networks are LAN (Local Area Network), Ethernet, FDDI and ATM. Advantageously the networks support broadcasting functionality.
Therefore also method of providing fault tolerant communication in a communication system supporting communication of packet data and comprising a number of distributing nodes, each of which comprises a number of processing means, is provided. The method comprises the steps of; interconnecting each processing means with all other processing means via at least two physically separated networks; sending first information messages from each processing means to all the other processing means with a given frequency (at least if needed; information obtainable through ordinary traffic may also be taken advantage of) using all of said at least two networks; providing information to at least the sending processing means about faults concerning first information messages sent from the respective sending processing means to the respective receiving processing means on the at least two networks substantially simultaneously; collecting information obtainable through the sending of said first messages for each of said processing means in information holding means using said information to detect errors in the communication paths; and using the information to control the communication between the respective processing means and to keep information about errors.
In a preferred implementation the first information messages comprise special purpose broadcast messages and the method further includes the steps of, when detecting an error, sending a second message comprising a special purpose unicast message to the sending processing means using all of said at least two networks. Alternatively the first messages are a burst of unicast messages.
Particularly the method comprises the steps of defining a time window for each processing means and if all first information messages from one and the same sending processing means using different networks do not arrive in a receiving processing means within the time window; informing the sending processing means. In a particular embodiment the method comprises the steps of, if an error is detected in the communication path when a particular network is used for sending of a message from a particular sending processing means, sending a unicast message to the sending processing means and if it is detected that there is a malfunctioning in the receiving processing means or an error on one of the networks, including information about that in the next first message, e.g. special purpose broadcast message of the receiving processing means which then is broadcasted using all the networks. In an alternative embodiment the method comprises the step of confirming reception of first messages in response, e.g. unicast messages sent to the respective sending processing means, using each network, to provide information about usable communication paths on every network and building a table with information about available communication paths using said response messages in each processing means.
According to different embodiments, as referred to above, the second messages or the response messages resulting from the sending of first messages are used to dynamically build an information table in the respective processing means. It is an advantage of the invention that a high availability on system level provided and that fault tolerant communication is provided in a way that is transparent to the users of the data link services. It is also an advantage that no single point of failures are provided and also that automatic error detection is provided for and that an automatic recovery is enabled. It is also an advantage that it is possible to handle dual unit transmitter/receiver errors even if they are located on separate networks as long as there exists at least one usable transmission path in each direction. According to the invention it is particularly possible to remove one whole network, e.g. a whole local area network, such as for example a switch, in operation without requiring any particular actions by the operator.

Arrangement, system and method relating to data/telecommunication