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WO2000027139A1 - Procede et systeme de communication point a multipoint dans lesquels des vecteurs de communication sont utilises - Google Patents

Procede et systeme de communication point a multipoint dans lesquels des vecteurs de communication sont utilises Download PDF

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Publication number
WO2000027139A1
WO2000027139A1 PCT/US1999/022352 US9922352W WO0027139A1 WO 2000027139 A1 WO2000027139 A1 WO 2000027139A1 US 9922352 W US9922352 W US 9922352W WO 0027139 A1 WO0027139 A1 WO 0027139A1
Authority
WO
WIPO (PCT)
Prior art keywords
wireless router
parameters
subscriber
subscriber subsystem
subsystem gateway
Prior art date
Application number
PCT/US1999/022352
Other languages
English (en)
Inventor
Bruce Dawson Swail
Original Assignee
Motorola Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Inc. filed Critical Motorola Inc.
Publication of WO2000027139A1 publication Critical patent/WO2000027139A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10—Small scale networks; Flat hierarchical networks
    • H04W84/14—WLL [Wireless Local Loop]; RLL [Radio Local Loop]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/24—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction
    • H01Q21/245—Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction provided with means for varying the polarisation 
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/22—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the orientation in accordance with variation of frequency of radiated wave

Definitions

  • the present invention generally relates to communication systems, and more particularly to method and point-to-multipoint communication system utilizing optimized communication vectors.
  • the conventional wireless communication systems typically have design air interface and system level parameters to achieve a uniform set of link parameters to be used across the entire subscriber population.
  • This uniform set of link parameters introduce an inefficiency, i.e., lower capacity, into the communication system.
  • the capacity of the communication systems is dictated by the best fit, lowest, or common denominator link parameters of the entire subscriber population in any communication system.
  • ASIC application specific integrated circuit
  • DAVIC Digital Audio Visual Committee
  • HCS header check sequence
  • HDLC high level data link control
  • FIG. 1 is an overview diagram of the wireless access system in accordance with the preferred embodiment of the invention.
  • FIG. 2 is a block diagram illustrating details of a wireless router of the system of FIG. 1.
  • FIG. 3 is a frequency spectrum diagram illustrating the wireless channel between the subscriber subsystem gateway and the wireless router of FIG. 1.
  • FIG. 4 illustrates a detailed block diagram representation of a wireless router in accordance with the present invention.
  • FIG. 5 is a flow chart representation of one embodiment of steps of a method for optimizing communication between at least one subscriber subsystem gateway and a wireless router in accordance with the present invention.
  • FIG. 6 is a representation of further steps following the steps of FIG.
  • FIG. 7 is an illustration of an exemplar subscriber subsystem gateway and a wireless router establishing communication in accordance with the present invention.
  • FIG. 8 illustrates a state diagram of the events causing an update of the discovery sequence in accordance with the present invention.
  • the present invention provides for a method and wireless communication system where the users, i.e., subscriber units, are either stationary or have very slow speed mobility, wherein optimized links are established for each subscriber unit such that the overall system capacity is enhanced.
  • the enhancement of the system capacity is a result of the summation of a series of the optimized communication links between each wireless router and the corresponding subscriber units of the communication system.
  • FIG. 1 illustrates a wireless access system in accordance with the preferred embodiment of the invention. It comprises a subscriber subsystem 10, which is preferably an in-premises system in a residential home or small business building. A number of such subsystems 11 to 15 are shown. Each has a subscriber subsystem gateway (e.g. gateways 20 and 22). Hereafter subscriber subsystem gateway 20 will be described by way of example and interchangeably referred to as residential gateway 20.
  • the residential gateway 20 is in communication with a roof-mounted antenna 21.
  • the antenna 21 communicates over a broad-band radio channel 25 with a wireless router 30.
  • a number of such wireless routers are illustrated, including wireless routers 31 , 32, and 33.
  • the wireless routers 30 to 33 are in communication with each other over radio links 34, 35, 36, and 37. Some of the wireless routers are connected to a global internet network 40. In the illustrated case, wireless routers 31 and 33 are connected to the global internet network 40.
  • each of the wireless routers 30, 31 , 32, and 33 is connected directly to the global internet 40.
  • the links 34, 35, 36, and 37 are replaced with land- based links such as a fiber distributed data interface (FDDI) network or 100Base-X links or an asynchronous transmission mode (ATM) network.
  • FDDI fiber distributed data interface
  • ATM asynchronous transmission mode
  • Other suitable connections are possible, including satellite links.
  • Connected to at least one of the wireless routers is a node station in the form of a network management module 50.
  • a physical link is established between residential gateway 20 and wireless router 30 for transfer of data of various types to and from the subscriber subsystem 10.
  • the establishment of a physical connection over the broad-band radio channel 25 is described in greater detail below and consists, in general terms, of identification by the residential gateway 20 of a pilot channel transmitted by the wireless router 30, identifying to the residential gateway 20 the existence of the wireless router and services or capabilities available from the wireless routers.
  • the residential gateway 20 uses the pilot channel as a guide, the residential gateway 20 transmits a request to the wireless router requesting registration. This request is forwarded by the wireless router over link 34 to network management module 50.
  • Network management module 50 responds to the request for registration and authorizes wireless router 30 to initiate communications with the residential gateway 20 and the subscriber subsystem 10.
  • the manner and extent of communication enabled depends on the level of service to which the subscriber responsible for the subscriber subsystem 10 has subscribed in the network management module 50.
  • Wireless routers can route communications directly from one subscriber subsystem to another subscriber subsystem served by the same router, or can link those communications over one of the links 34, 35, 36, and 37 to an adjacent or remote wireless router in the system, for onward communication to another subscriber subsystem. Additionally and alternatively one of the wireless routers (e.g. wireless router 31) can route communications from a subscriber subsystem into the global internet network 40.
  • the wireless router 30 comprises multiple wireless receiver cards 200, 201 , etc. and multiple wireless transmitter cards 210, 211 , etc. There is one transmitter card and one receiver card for each radio band connecting the wireless router 30 with the subscribers that it serves. Suitable radio bands are in the 2.5 GHz radio band, the 5 GHz radio band, the 28 GHz radio band and other high frequency bands. It is not necessary for the wireless router 30 to serve multiple radio bands. Any one of these radio bands will suffice for the system. Accordingly, at a minimum there is just one wireless transmitter card and one wireless receiver card.
  • the transmitter and receiver cards 210, 211 , 200 and 201 are connected to a wireless router bus 202.
  • a controller Also connected to the bus are a controller and one or more interface cards for linking the wireless router to other wireless routers or to the global Internet or other networks.
  • These interface cards include a wireless network interface 230, a FDDI network interface 231 , a 100Base-X interface 232, an ATM network interface 233, and another network interface card 234.
  • the network interface cards 233 and 234 perform the tasks of ATM layer segmentation and reassembly (SAR), and forwarding, or layer 3 routing and forwarding, with or without bridging. Packets or frames are transmitted to the appropriate network after these functions are performed.
  • SAR layer segmentation and reassembly
  • Packets or frames are transmitted to the appropriate network after these functions are performed.
  • the wireless router 30 has a central controller 221 with a memory
  • Each of the cards 200 or 210 or 221 or 230 to 234 also has a processor or controller (e.g. a microprocessor or an ASIC).
  • the various controllers or processors have loaded therein software that performs certain functions as follows.
  • the controller 221 performs routing protocols, signaling functions, MAC protocol scheduling and spectrum management and it includes SNMP agents.
  • the wireless transmitter cards 210 and 211 perform MAC protocol formatting and processing and perform spectrum management.
  • the wireless receiver cards 200 and 201 perform MAC protocol formatting and processing, spectrum management, IP, MPEG and/or ATM forwarding.
  • the wireless network interface 230 performs MPEG forwarding and spectrum management for the link 34.
  • the FDDI network interface 231 performs IP forwarding, as does the 100Base-X interface 232.
  • the ATM network interface 233 performs IP forwarding, ATM forwarding and MPEG forwarding.
  • IP Internet Protocol
  • MPEG MPEG or other compressed video needs to be transferred between an audio visual transport card (not shown) or the video processor (not shown) of the subscriber device and either the wireless network interface card 230 or the ATM network interface card 233.
  • ATM cells may need to be transferred between the ATM network interface card 233 and one of the other interface cards, for example a USB interface (not shown) or an in-home bus transceiver (not shown).
  • All these data types need to be supported simultaneously, but with differing requirements, for example, differing quality of service (QoS) requirements.
  • QoS quality of service
  • telephone voice traffic it is desirable for telephone voice traffic to be transferred through the system with minimum delay so that telephone conversations are not disrupted by excessive delays in the 2-way connection.
  • Ethernet and IP data packets can generally tolerate longer delays in end-end transfers. The challenge is to support all these high bandwidth, high data rate packet types on a common radio channel, which inherently has limited bandwidth, for example, typically less bandwidth than an optical fiber or coaxial cable.
  • the residential gateway 20 there is an initialization between the residential gateway 20 and the network management module 50.
  • a pilot channel on the radio channel 25 This is illustrated in FIG. 3.
  • FIG. 3 Considering the entire bandwidth available for the radio channel 25, stretching from f a to f b , there is a downstream pilot channel 300 broadcast by the wireless router 30 to any subscriber subsystem wishing to initialize.
  • These channels are illustrated at the lower end of the available radio bandwidth.
  • the available bandwidth may, for example, be in the range 5.0-5J GHz, but other bandwidths at 2.4 GHz or 28 GHz could equally suffice.
  • All wireless routers 30, 31 , 32 and 33 use the same frequencies for the upstream and the downstream pilot channels 301 and 300.
  • the modulation (at least on the downstream) is common to all wireless routers.
  • the modulation can be QPSK, FSK or QAM (e.g. 64 QAM).
  • the downstream framing for the pilot channel is the same for all wireless routers and is preferably synchronous, based on HDLC and/or DAVIC specified framing.
  • a new subscriber unit or residential gateway that is not previously registered with the network management module 50 goes to the known downstream broadcast pilot channel upon power up.
  • This downstream pilot channel periodically broadcasts a spectrum description map of all the channels/carriers available in the entire spectrum from f a to f , as well as parameters associated with those channels, including cutoff frequencies, modulation, upstream or downstream channel, associations between upstream and downstream channels, etc.
  • the downstream frame format comprises a flag, followed by a number of controlled bits, followed by the downstream spectrum description map, followed by FCS or FEC coding and finally a flag, after which the frame repeats.
  • FCS or FEC coding FCS or FEC coding
  • the network management module 50 sends a message through wireless router 31 and through wireless router 30 to subscriber subsystems served by the wireless router 30 (and indeed to all subscriber subsystems served by all wireless routers) inviting new unregistered subscriber devices to register themselves with the system.
  • This request is sent on the downstream pilot channel 300.
  • a new subscriber device receiving this invitation can match itself up with the channel rate and modulation described in the downstream spectrum description map. Alternatively, it can choose to try to introduce a new channel into the spectrum, specifying its own parameters for the new channel.
  • the message from the subscriber device to the wireless router 30 is over a shared upstream channel 301.
  • the wireless router Upon receipt by a wireless router 30 of an acknowledgment from network management module 50, the wireless router transmits to the requesting subscriber device a set of channel parameters defining a channel that is being allocated to that subscriber device.
  • the set of channel parameters is transmitted in the downstream pilot channel.
  • the channel parameters transmitted to the requesting subscriber device include the frequency range for the channel allocated, for example, F X
  • preferably define a channel within the total available bandwidth such that several similar channels can co-exist in a frequency division multiplex manner.
  • a suitable channel width is 20 MHz in the 5.0-5J GHz range - i.e. each channel consuming approx. one fifth of the available bandwidth and allowing up to five such channels to be set up side- by-side.
  • these figures are approximate as a small amount of bandwidth must be set aside for the pilot channels 300 and 501 and for guard bands between channels.
  • FIG. 3 is not to scale.
  • the above described initialization procedures are controlled and operated by software located in the system manager (not shown) of the residential gateway 20 and the controller 221 of the wireless router 30, as well as software located in the network management module 50. In this manner, a channel is established between the residential gateway 20 and the wireless router 30.
  • FIG. 4, numeral 400 illustrates a detailed block diagram representation of a wireless router in accordance with the present invention.
  • the wireless router 30 includes a receiving/transmitting portion 402 and a control/processing portion 404.
  • the receiving/transmitting portion 402 includes an antenna 406, an amplifier 408, a demodulator 410, a decoder 412, a modulator 414, an intermediate frequency (IF) generator 416, a radio frequency (RF) generator 418, and a power amplifier 420.
  • the antenna 406 receives and transmits information that are in part in the form of test or acknowledgment messages. Upon receiving signals, the antenna provides the signals to the amplifier 408 for amplification.
  • the decoded signal output from the decoder 412 is supplied to the control/processing portion 404.
  • the control/processing portion 404 includes a messaging processor 422, a message generator 424, a power control unit 426, a beam adjuster 428 a controller 430, and a modulation control 432.
  • the decoded signals provide a bit error rate (BER) signal 413 to the controller 430 indicating the level of accuracy of the received information from the subscriber subsystem gateway. Moreover, the decoded signals are supplied to the messaging processor 422.
  • the messaging processor 422 processes the message contained in the decoded signals.
  • the message includes a cyclic redundancy check (CRC) portion that is utilized by the messaging processor 422 for error detection in the received message.
  • CRC cyclic redundancy check
  • the controller 430 is connected to the modulation control 432, message generator 424, power control unit 426, and beam adjuster 428.
  • the controller 430 determines the acceptability of the received message based on the BER signal 413 from the decoder 412 and the detected error level from the messaging processor 422. In the event the BER of the received message is acceptable and there is sufficient signal strength, the controller signals the power control unit 426 to reduce the power level of the transmission power. In contrast, when the BER of the received message is not acceptable, the controller 430 signals the modulation control 432 to lower the modulation order or increase power until the BER of the received message is acceptable.
  • the modulator 414 modulates a set of messages generated by the message generator 424 and provides each set of messages to the IF and RF generators.
  • One of the messages of the set of messages from the wireless router 30 is a test message for transmission to the subscriber subsystem gateway 20.
  • FIGs. 5 and 6 are a flow chart representation of one embodiment of steps of a method for optimizing communication between at least one subscriber subsystem gateway (hereafter referred to as "subscriber") and a wireless router in accordance with the present invention.
  • a wide beam e.g. a 120° sector beam
  • ACK acknowledgment
  • the elevation and/or the azimuth angle for the antenna of the wireless router is adjusted (e.g. by selecting a different 120° sector).
  • step 510 is whether the beam aperture transmitting the test message is the narrowest beam.
  • the beam aperture is not the narrowest beam (which will greatly be the case at the commencement of the process)
  • the beam aperture is reduced at step 502 (for example by halving the beam angle)
  • the process is repeated through steps 504 to 510.
  • the foregoing steps provide for adjusting the beam aperture such that the subscriber is located and the beam aperture is reduced to the narrowest size (i.e. a predetermined desired beam width) without losing communication with the subscriber.
  • FIG. 6 is a representation of further steps following the steps of FIG. 5 of the method for optimizing communication between at least one subscriber subsystem gateway and a wireless router in accordance with the present invention.
  • step 602 when the signal strength of the received message is sufficient, then at step 604 the power level is reduced by a step or increment and the process repeats until step 602 identifies that the power has been reduced too far, whereupon at step 606 the power level is increased by one step increment and flow proceeds to step 608, where an inquiry is made as to whether the BER is acceptable. In the event that the BER is acceptable, then at step 610 the modulation order is raised to achieve a high data rate and this process is repeated until the BER is no longer acceptable.
  • the modulation order is stepped up from (for example) PSK (lowest order) through QPSK, QAM, 16QAM, 32QAM, 64QAM, up to the maximum modulation order supported by the system.
  • PSK lowest order
  • QAM quadrature QAM
  • 16QAM 16QAM
  • 32QAM 32QAM
  • 64QAM 64QAM
  • the modulation order is lowered one level at step 612.
  • a set of parameters are stored in the wireless router for providing an optimal communication between the wireless router and the subscriber device.
  • the above-described method of the present invention generally provides for optimizing communication between at least one subscriber subsystem gateway and a wireless router by: a) directing a beam from an antenna of the wireless router having a predetermined size aperture for covering a predetermined area; b) locating the at least one subscriber subsystem gateway; c) focusing the beam on the subscriber subsystem gateway; d) optimizing the physical link to maximize data throughput.
  • a set of parameters is established in a form of a communication vector between the at least one subscriber subsystem gateway and the wireless router, wherein the set of parameters are specific to the at least one subscriber subsystem gateway.
  • the present invention provides for an optimum communication path, between a subscriber and a wireless router, that is determined through a discovery sequence according to the method described above.
  • a set of parameters in a form of a communication vector is stored in the memory 222 of the wireless router 30.
  • Four such parameters have so far been described, viz. beam aperture, beam elevation and azimuth and modulation order, but it will be appreciated that these are just examples of a more generic set of physical link parameters that together form a communication vector.
  • Each subscriber in the communication system has a specific and optimal communication vector associated with it.
  • Each communication vector defines all attributes of a communication link between each subscriber and the associated wireless router.
  • the present invention provides for a novel feature wherein each time a communication is desired between the wireless router and a subscriber the communication vector associated with the subscriber is accessed from memory 222 in the wireless router, or from the network (e.g. in the network management module 50 or other central controller) and a communication is established accordingly.
  • the process of accessing the communication vector is effected by utilizing a table stored in the memory 222 of wireless router, for example, wherein the table provides for correlating a subscriber identification with an associated communication vector.
  • the set of parameters of the communication vector for each subscriber includes a subset of link parameters and another subset of antenna steering parameters.
  • the antenna steering parameters include at least one of: antenna azimuth; antenna elevation angle; antenna aperture size; and antenna polarization. Azimuth, elevation and aperture size setting have already been discussed and explained. Antenna polarization can be set in the same way.
  • the link parameters include at least one of: forward error correction coding; depth of forward error correction coding; automatic retransmission request (ARQ); effective isotropic related power (EIRP) for the wireless router; EIRP for the at least one subscriber subsystem gateway; and power save interval. These parameters can be optimized and set in a manner similar to the optimizing of the modulation order already described.
  • FIG. 7, numeral 700 is an illustration of an exemplar subscriber subsystem gateway and a wireless router establishing communication in accordance with the present invention.
  • a TEST message 702 is transmitted from the wireless router 30 to the subscriber 20.
  • the subscriber 20 receiving the TEST message 702 demodulates and decodes the TEST message 702 utilizing demodulator 704 and decoder 706 respectively.
  • a BER of the received TEST message 702 is determined and provided to a message generator 708 in the subscriber subsystem gateway 20.
  • An ACK message 710 is generated by the message generator 708 and transmitted to the wireless router 30.
  • step 506 when the ACK message is received by the wireless router it is determined whether the size of the antenna beam is narrowest and the remaining steps are taken.
  • FIG. 8, numeral 800 illustrates a state diagram of the events causing an update of the discovery sequence in accordance with the present invention.
  • the process begins at the beginning state 802.
  • an initial training/discovery sequence according to the method described above with reference to FIGs. 6 and 7 is implemented and the set of parameters are optimized and stored in the memory of the wireless router.
  • state 806 the active communication between the wireless router and the subscriber device is established. In the event the network requests a retraining/rediscovery sequence a transition 808 can take place to state 804.
  • a retraining may be effected at state 810 if one of the following three conditions are met: first, when there is a time-out request made by the wireless router resulting in transition 812; second, when there is accumulative excessive retransmit requests by the wireless router to subscriber resulting in transition 814; or third, off-peak retraining request is made resulting in transition 816. If the retraining is successful, a transition 818 is made to the active communication state 806; whereas if the retraining fails, a transition 820 is made to the initial training state 804. Retraining would be the reverse order of initial training.
  • the present invention has provided a method and system with the benefit of having predetermined communications vectors as a quick shorthand approach to support optimized communications between at least two points, for example, a wireless router and a subscriber.
  • the initial training and periodic retraining result in the routine communications not requiring a calibration period as is common on dial up analog modems.
  • the optimized link (communication vector) is stored/'Yemembered" over time. Thus each communication session/burst can concentrate on data (payload) communication without excessive system overhead.
  • Each subscriber has a unique (optimized) communication vector relative to a shared wireless router. This results in system capacity which is the integral (summation) of optimized links rather than the sum of a series of worst case links (lowest common denominator) which is the conventional method of establishing communication between a plurality of subscribers and a shared wireless router.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un procédé et un système de communication point à multipoint, dans lesquels sont prévus au moins une passerelle de sous-système d'abonné (20) et un routeur sans fil (30) conçu pour communiquer avec la ou les passerelles (20). Ledit routeur sans fil (30) possède une mémoire pour la mémorisation d'un ensemble de paramètres sous la forme d'un vecteur de communication établi par un échange d'apprentissage avec la ou les passerelles de sous-système d'abonné (20), l'ensemble de paramètres étant spécifique de la ou desdites passerelles (20).
PCT/US1999/022352 1998-10-30 1999-09-28 Procede et systeme de communication point a multipoint dans lesquels des vecteurs de communication sont utilises WO2000027139A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US18408898A 1998-10-30 1998-10-30
US09/184,088 1998-10-30

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WO2000027139A1 true WO2000027139A1 (fr) 2000-05-11

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002063836A3 (fr) * 2001-02-09 2003-04-17 Nokia Corp Systeme de communication de donnees
JP2017169220A (ja) * 2011-08-11 2017-09-21 サムスン エレクトロニクス カンパニー リミテッド 無線通信システムにおけるビーム追跡方法及び装置

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Publication number Priority date Publication date Assignee Title
US5852405A (en) * 1995-03-17 1998-12-22 Fujitsu Limited Wireless LAN system
US5914946A (en) * 1996-11-08 1999-06-22 Lucent Technologies Inc. TDM-based fixed wireless loop system

Patent Citations (2)

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Publication number Priority date Publication date Assignee Title
US5852405A (en) * 1995-03-17 1998-12-22 Fujitsu Limited Wireless LAN system
US5914946A (en) * 1996-11-08 1999-06-22 Lucent Technologies Inc. TDM-based fixed wireless loop system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002063836A3 (fr) * 2001-02-09 2003-04-17 Nokia Corp Systeme de communication de donnees
JP2017169220A (ja) * 2011-08-11 2017-09-21 サムスン エレクトロニクス カンパニー リミテッド 無線通信システムにおけるビーム追跡方法及び装置
US10148331B2 (en) 2011-08-11 2018-12-04 Samsung Electronics Co., Ltd. Method and apparatus for tracking beam in wireless communication system

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