CN1204441A - Bandwidth allocation - Google Patents

Abstract

A method for reassigning mobile stations a new phase within a channel is disclosed. In a communication system, a plurality of mobile stations attempt to communicate on a limited number of channels. The invention first uses a general allocation method to approximately evenly distribute the mobile stations on the available channels. After a mobile station begins active communication on the system, a second allocation method is used to change the phase of some mobile stations on a channel which has become heavily loaded. In addition, a message can also be sent to mobile stations assigned to but not yet actively communicating on the heavily loaded channel indicating that the mobile stations should change to a new channel.

Description

Allocated bandwidth

Applicant's invention relates to telecommunication, be particularly related to wireless communication system, such as being used for (the simulation of various operator schemes, numeral, double mode etc.) honeycomb and satellite radio systems, and access technology is such as frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA) and the FDMA/TDMA/CDMA that mixes.The concrete aspect of the present invention is especially at the allocated bandwidth that strengthens, the technology of the throughput of traffic carrying capacity and capacity management and transaction.

Narration is at using environment of the present invention below.This general description is the general general introduction that known system and correlation technique will be provided, so that can understand the present invention better.

In the North America, digital communication and multiple access technology such as TDMA is provided by the digital cellular radiotelephone systems that is called advanced digital cellular phone service (D-AMPS) at present, some features are at interim standard TIA/EIA/IS-54-B, by " dual mode mobile station-base station compatible standard " middle regulation that telecommunications industry association and Electronic Industries Association (TIA/EIA) publish, the TIA/EIA/IS-54-B standard is introduced for reference in the present invention.Because existing in a large number consumer is based on apparatus operating in the analog domain with frequency division multiple access (FDMA) only, TIA/EIA/IS-54-B is double mode (analog-and digital-) standard, is used for simulation and digital communicating ability compatibility.For example, the TIA/EIA/IS-54-B standard provides FDMA analog voice channel (AVC) and TDMA digital service channel (DTC).AVC and DTC utilize radio carrier frequency modulation is realized that this carrier signal has near 800 megahertzes (MHz) frequency, makes each radio channel have the frequency spectrum of 30 kilo hertzs (KHz).

In the TDMA cellular radiotelephone system, each wireless channel is divided into a series of time slot, and each time slot comprises the signal pulse series from for example digitally coded voice conversation part of data source.These time slots are grouped into the continuous tdma frame with scheduled duration.Timeslot number in each tdma frame is relevant with the different user number that can share radio channel simultaneously.If each time slot allocation in the tdma frame is given different users, then the duration of tdma frame is the minimum time amount of distributing between same user's the continuous time slot.

The continuous time slot of distributing to same user is not the time slot that links to each other usually on this radio carrier, and they constitute user's digital service channel, and this Traffic Channel can think to distribute to this user's logic channel.As narration in more detail below, digital control channel (DCC) also can be provided for communications control channel, and such DCCH is the logic channel that is made of a series of time slots that do not link to each other on radio carrier usually.

Only as one of the many possible embodiment of above-mentioned tdma system in, the TIA/EIA/IS-54-B standard provides each tdma frame to comprise six continuous time slots and has the duration of 40 milliseconds (ms).Therefore, depend on the source speed of the speech coders/decoders (codec) of this session that is used for digitally encoding, each radio channel can be transmitted three to six DTC (for example three to six telephone conversations).Such audio coder ﹠ decoder (codec) can full rate or half rate work.During requiring during preset time, full rate DTC doubles the time slot of half rate DTC, and in TIA/EIA/IS-54-B, each full rate DTC uses two time slots of each tdma frame, and for example the first and the 4th, second and the 5th or the 3rd and the 6th of six of a tdma frame time slots the.Each half rate DTC uses a time slot of each tdma frame.During each DTC time slot; send 324 bits; its major part 260 bits are results of the voice output of codec, comprise because the result's of the error correction coding of voice output bit and all the other bits are used for guard time and the expense signaling that is used for such as synchronous purpose.

Can find out that the TDMA cellular system is with buffering and burst or discontinuousness transmission mode work: each mobile radio station only sends (and reception) during the time slot of its appointment.In full rate, for example mobile radio station can send during time slot 1, receives during time slot 2, and is idle during time slot 3, sends during the time slot 4, in reception during the time slot 5 and idle during time slot 6, repeats this circulation then during tdma frame subsequently.Therefore, may be that battery powered mobile radio station does not neither send when not receiving yet and can be shut down or sleep at it, to save the power supply during these time slots.

Except voice or Traffic Channel, cellular radio communication system also provides paging/access and control channel, is used for transmitting call setup message between base station and mobile radio station.According to TIA/EIA/IS-54-B, the Analog Control Channel (ACC) of 21 special uses is for example arranged, these channels have and are positioned at the predetermined fixed frequency that is used to send and receive near 800MHz.Because these ACC always find in identical frequency, they can be positioned and be monitored by this mobile radio station at an easy rate.

For example, when being in idle condition (power connection does not still carry out or receipt of call), mobile radio station in the TIA/EIA/IS-54-B system be tuned to and monitor the strongest control channel (be generally speaking at that control channel of this mobile radio station place mesh) constantly then regularly, and can receive and originating call by relevant base station.When mobile radio station moves between mesh when being in idle condition simultaneously, this mobile radio station even " losing " the dedicated radio link of the control channel of " old " mesh and be tuned to the control channel of " newly " mesh.Initial tuning and subsequently retune control channel the two be by from their known frequency scannings can with control channel so that find the control channel of " best " automatically to realize.When finding the control channel with good quality of reception, this mobile radio station still is tuned at this channel till quality worsens again.Like this, mobile radio station keeps " contacting " with this system.

When idle condition, mobile radio station must monitor the control channel of its beep-page message of addressing.For example, when common phone (landline) customer call mobile subscriber, this calling is sent to the mobile switching centre (MSC) that analyzes this dialed number from public switch telephone network (PSTN).If dialed number is effective, MSC asks some or all base stations of a plurality of radio base stations to come the called mobile radio station of paging through their control corresponding channels transmission beep-page message, and this beep-page message comprises the mobile identification code (MIN) of called mobile radio station.The MIN that store itself MIN that the idle mobile radio station of each of paging receiving message relatively receives and it.Mobile radio station with the MIN that meets storage sends page response for this base station through specific control channel, and this base station is transmitted this page response and given MSC.

When receiving page response, AVC or DTC that the MSC selection can be used for the base station that receives this page response, connect the corresponding radio set in that base station, with make that base station send a message to called mobile radio station through this control channel, order this called mobile radio station be tuned to speech or the Traffic Channel selected.In case this mobile radio station has tuned to selected AVC or DTC, just set up the connection of calling out.

Performance with system of the ACC that is stipulated by TIA/EIA/IS-54-B has been improved in the system with digital control channel (DCCH) of stipulating in TIA/EIA/IS-136, and TIA/EIA/ZS-136 quotes at this as a reference specially.Use such DCCH, each TIA/EIA/IS-54-B radio channel portability has only DTC, the two mixes to have only DCCH or DTC and DCCH.In the TIA/EIA/IS-136B structure, each radio carrier frequency can have the DTC/DCCH of three full rates of as many as or the DTC/DCCH of six half rates, the perhaps any combination between them, for example, a full rate and four half rate DTC/DCCH.

But usually, the transmission rate of DCCH does not need consistent with half rate and the full rate stipulated among the TIA/EIA/IS-54-B, with the length of DCCH time slot can disunity and the length with the DTC time slot is not consistent.DCCH can define on the TIA/EIA/IS-54-B rate channel and for example can be made of each the n time slot in the tdma slot stream that links to each other.In this case, the length of each DCCH time slot can equal maybe can be not equal to 6.67ms, and 6.67ms is the length according to the DTC time slot of TIA/EIA/IS-54-B.Selectively (with may select without limits other), these DCCH time slots can be with alternate manner definition well known by persons skilled in the art.

In cell phone system, require airlink protocols, so that allow mobile radio station to communicate by letter with base station and MSC.The communication link agreement is used to start and receive cellular calls.Communication link agreement in communication industry is commonly referred to second layer agreement, and its function comprises delimits and the 3rd layer of message of framing.These the 3rd layer of message can be in residing in mobile radio station communication layers 3 peer entities and the honeycomb switching system between send.The parameter of physical layer (ground floor) definition physical communication channels, for example radio frequency interval, modulating characteristic etc.Information in second layer definition physical channel limits is the required technology of transmission accurately, for example error correction and error detection etc.The 3rd layer of process that is defined in the reception and the processing of the information that sends on the physical channel.

Communicating by letter and to carry out general description with reference to Fig. 1 and Fig. 2 between mobile radio station and the honeycomb switching system (base station and MSC).Fig. 1 schematically represents the frame 13 of a plurality of the 3rd layer of message 11, the second layer and the channel pulse string or the time slot 15 of ground floor.In Fig. 1, can constitute a logic channel corresponding to every group of channel pulse string of each the 3rd layer of message, and as mentioned above, on the TIA/EIA/IS-136 carrier wave, or not the time slot that link to each other usually for the channel pulse string of the 3rd layer given message.On the other hand, this channel pulse string can link to each other, and a time slot finishes just to begin next time slot.

Each ground floor channel pulse string 15 comprises for example error correction information and be used for other Overhead of ground floor operation of a complete second layer frame and out of Memory.The Overhead that each second layer frame comprises a part of at least the three layer and is used for second layer operation, though not expression in Fig. 1, each message of the 3rd layer can comprise various information units, and the load of this message, the title division of identification corresponding message type and possible filling part can be thought in these unit.

Each ground floor pulse train is divided into a plurality of different fields with each second layer frame.Particularly finite length data (DATA) field in each second layer frame comprises the 3rd layer of message 11.Owing to depend on the amount of information that comprises in the 3rd layer of message, the 3rd layer of message has variable-length, needs a plurality of second layer frames in order to send single the 3rd layer of message.As a result, send whole the 3rd layer of message and also may need a plurality of ground floor channel pulse strings because between channel pulse string and the second layer frame man-to-man corresponding relation is arranged.

As noted above, when requiring more than one channel pulse string to send the 3rd layer of message, several pulse trains are not the pulse trains that links to each other on radio channel usually.And, several pulse trains even normally be exclusively used in the disjunct pulse train of the special logic channel that transmits the 3rd layer of message.Because to reception, processing and the reaction needed time of the pulse train of each reception, send the pulse train that the 3rd layer of message requires and send with stagger scheme usually, as being narrated in conjunction with the TIA/EIA/IS-136 standard of schematically illustrating at Fig. 2 (a) with top.

Fig. 2 (a) expression be included in the continuous time slot 1,2 that sends in the carrier frequency, in continuous time slot 1,2 ..., N ... some examples of forward direction (or down link) DCH that constitutes.These DCCH time slots can define on radio channel, as by TIA/EIA/IS-136 regulation, and as seeing at Fig. 2 (a), can be made of every n the time slot in a series of continuous time slots.Each DCCH time slot has can be or can not be the duration of 6.67ms that this duration is the length corresponding to the DTC time slot of TIA/EIA/IS-136 standard.

As Fig. 2 (a) see that the DCCH time slot can be arranged to super frame (sf), each superframe comprises a plurality of logic channels that transmit different types of information.One or several DCCH time slot can be distributed to each logic channel in this superframe.The down link superframe of the example in Fig. 2 (a) comprises three logic channels: the Broadcast Control Channel (BCCH) that comprises six continuous time slots that are used for Overhead Message; The paging channel (PCH) that comprises a time slot that is used for beep-page message; With the access responsive channels (ARCH) that comprises a time slot that is used for channel allocation and other message.All the other time slots in the example superframe of Fig. 2 (a) can be exclusively used in other logic channel, such as additional paging channel PCH or other channel.Because the quantity of mobile radio station is more much bigger than the timeslot number in this superframe usually, each paging time-slot is used for last several mobile radio stations that certain unique character such as MIN are shared in paging.

Fig. 2 (b) expression is used for the preference information form of the time slot of forward direction DCCH.The information that transmits in each time slot comprises a plurality of fields, and Fig. 2 (b) is illustrated in the bit number in each field on that field.The bit that sends in SYNC (synchronously) field is used to guarantee the superframe phase place (CSFP) of encoding and the accurate reception of DATA (data) field in the mode of routine.The SYNC field comprises the predetermined bit sign indicating number type that is used by the base station, so that find the beginning of this time slot.Shared channel feedback (SCF) field is used to control Random Access Channel (RACH), and this channel is used for request by mobile radio station and inserts this system.The superframe phase value of CSFP field transmission coding, this value makes mobile radio station can find the beginning of each superframe.This only is an example of information format in the time slot of forward direction DCCH.

For effectively sleep mode operation and the purpose of mesh selection fast, BCCH can be divided into a plurality of subchannels.The BCCH structure represents that (when it is locked in DCCH) allows this mobile radio station to read the information of minimum inserting this system (sending or receipt of call) before when it is connected.After connecting, idle mobile radio station need be the appointment PCH time slot (time slot of each superframe usually) that monitors it regularly; This mobile radio station can be slept during other time slot.The ratio that mobile radio station is read beep-page message institute's time spent and its sleep institute's time spent be controllable and also represent delay in call establishment and electrical source consumption between compromise.

Because each tdma slot has certain fix information transfer capacity, each pulse train typically only transmits the part of the 3rd layer of message, and is as noted above.At uplink direction, a plurality of mobile radio stations are attempted on connection basis and this system communication, and a plurality of mobile radio stations are intercepted the 3rd layer of message that sends in the down link direction from this system simultaneously.In known system, any the 3rd layer of given message must use the desired many like that TDMA channel pulse strings of whole the 3rd layer of message of transmission to transmit.

Digital control and Traffic Channel is desirable such as supporting between the long sleep period of this mobile unit, and this obtains long battery life.Digital service channel and digital control channel have been expanded the optimization system capacity and have been supported that the hierarchical network pore structure is the function of grand mesh, microgrid hole, slight mesh etc.Term " grand mesh " refers generally to have the size of comparing with mesh size in conventional cell phone system (for example at least about 1km radius), and the mesh that term " microgrid hole " and " mesh slightly " refer generally to diminish gradually.For example, the microgrid hole can cover a public indoor or outdoors zone, and as conference centre or busy street, mesh can cover office corridor or one deck of high building slightly.From radio covering aspect, grand mesh, microgrid hole and slight mesh differ from one another or can overlap each other so that handle different business figure or radio environment.

Fig. 3 is cellular system classification or multilayer of an example.The grand mesh of representing with hexangle type 10 of umbrella constitutes an overlapping honeycomb.Each umbrella mesh can comprise the microgrid pore structure of a bottom.The grand mesh 10 of umbrella comprises with the microgrid hole 20 of the region representation that comprises in dotted line and with corresponding to along the microgrid hole 30 of the region representation that comprises in the dash line in the zone in street, city with cover the slight mesh 40,50 and 60 of building individual layer.Cross section by microgrid hole 20 and 30 street, two cities that cover may be the concentrated area of a dense traffic, therefore may represent a focus.

Fig. 4 representative comprises the mobile radio telephone system of an example of the base station 110 of example and mobile radio station 120.This base station comprises control and processing unit 130, and it is connected to MSC 140, and the latter is connected to the PSIN (not shown) again.The general aspect of such cellular radiotelephone system is well known in the art, and " switch in the adjacent auxiliary district of crossing in the cellular communication system " narrated as being called by people's such as Wejke United States Patent (USP) 5175867, name, quotes for reference in this application.

Base station 110 is by handling a plurality of voice channels by the control and the voice channel transceiver 150 of processing unit 130 controls.And each base station comprises a control channel transceiver 160, and it can handle more than one control channel.Control channel transceiver 160 is by control and processing unit 130 controls.Control channel transceiver 160 broadcast control information on the control channel of base station or mesh is given the mobile radio station that locks onto that control channel.Should understand that transceiver 150 and 160 can be used as the reasonable sound of individual equipment and realizes like that with control transceiver 170, uses with the DCCH and the DTC of shared same radio carrier frequency.

Mobile radio station 120 is received in the information of broadcasting on the control channel of its speech and control transceiver 170.Then, the control channel information of processing unit 180 these receptions of assessment, this control channel information comprises the feature of the candidate mesh of this mobile radio station locking.And determine that this mobile radio station should be locked in that mesh.Advantageously, the control channel information of this reception not only comprises the absolute information of relevant its relevant mesh, and comprise the relevant relative information that approaches other mesh of the relevant mesh of control channel, be called described in the United States Patent (USP) 5353332 of " method and apparatus of Control on Communication in radio telephone system " as the name people such as Raith, this patent citation is for reference in the application's book.

In order to increase user " talk time ", it is the battery life of mobile radio station, a digital forward control channel (base station is to mobile radio station) can be provided, this channel can transmit the type of message to present analogue forward control channel (FOCC) defined, still with such form: allow to lock onto FOCC and after this only read Overhead Message when this information has changed at idle mobile radio station; In all this mobile radio station sleeps At All Other Times.In such system, utilize the base station to broadcast some type of messages more continually, and mobile radio station needn't be read each information broadcast than other type.

System by TIA/EIA/IS-54-B and TIA/EIA/IS-136 standard code is a circuit-switched technology, and it is the type of " towards connecting " communication, sets up a physical call connection and is just keeping that connection as long as the communication ends system changes data.Circuit-switched direct connection allows end system to use this circuit when they see fit as the pipe-line of opening.Though circuit switched data communication also can be suitable for fixed bandwidth applications, it is relative inefficient using with " multi-pulse train (bursty) " for low bandwidth.

May be not require towards the packet-switch technology that connects (for example X.25) or " do not have and connect " (for example Internet Protocol " IP ") to set up and the disconnection physical connection that this is obviously opposite with circuit-switched technology.In short relatively, multi-pulse train or interactive transaction, reduced the efficient of data processing time and increase channel.The connectionless packet switching network distributes routing function to give a plurality of Route Selection websites, thereby the traffic bottleneck that may occur when having avoided the main frame of heart exchange in use.Data are independently sending in the unit along data path then with suitable end system addressed packet.The intermediate system that is fixed between the communication ends system is sometimes referred to as " router ", and only route is adopted in decision on the basis of each grouping.The Route Selection decision is according to numerous characteristics, comprising: minimum charge route or high cost tolerance; The capacity of link; Etc. packet count to be sent; Safety requirements to link; And intermediate system (node) operating state.

Transmitted in packets along the route of considering path metric is opposite with single circuit foundation, and it provides uses and the flexibility of communicating by letter.The Local Area Network and the wide area network (WAN) that in common environment, how to adopt standard have also been developed.Packet switching is suitable for data communication, because the equipment of many application and use such as keyboard terminal are interactively and send data with pulse train.Importing many data the user gives this terminal or stops that a channel is not idle when thinking a problem, a plurality of this channels that are transferred to that the packet switching interleave comes from several terminals.

Because the independence in path and when the network node fault router select the ability of alternate route, grouped data provides network firmer.Therefore, packet switching allows more effectively to use network line.Group technology provides charging according to the data volume that sends rather than connect hours to the user selection.Use airlink effectively if designed end user's application, then the packet count of Fa Songing is minimum.If it is minimum that each individual consumer's traffic carrying capacity keeps, then service supplier has increased the capacity of network effectively.

Usually packet network is designed and according to the standard of industrial scale, such as open system interface (OSI) model or ICP/IP protocol group.Though these standards formal or developed in fact for many years and use the application of these agreements to be easy to obtain.The main purpose of measured network is the interconnection of acquisition and other network.The internet is the most tangible example of obtaining so measured network of this target at present.

Packet network is similar to internet or common LAN, and it is a comprehensive part of commercial affairs at present and communication environment.Because mobile computing becomes more general in these environment, wireless traffic supplier such as the service supplier that uses TIA/EIA/IS-136 is in provides the desired positions that inserts these networks.In any case, cellular system is provided or the data service advised generally is based on the circuit switched operation pattern, use the radio channel of each movable mobile subscriber's special use.

Narrate in several exceptions file below based on the data service of the cellular system of circuit switched operation pattern, comprise the grouped data notion.

The article of United States Patent (USP) 4887265 and Proc.38th IEEE Vehicular TechnologyConf. 414-418 page or leaf (1988.6) " packet switching in the Digital Cellular System " has been narrated provides the cellular system of sharing the data packet radio channel, and each channel can hold a plurality of data calls.Require the mobile radio station of Packet data service to be assigned to the use specific cluster data channel of the cellular signaling of rule basically.This system can comprise the grouping access point (PAP) with the packet data network interface.Each data packet radio channel is received a specific PAP, therefore can the multiplexed data call relevant with that PAP.Conversion is to be begun to be substantially similar to the conversion regime that uses in the identical systems that is used for voice call by this system.When the off-capacity of grouped channels, add a new translation type for these situations.

These files be data-oriented-calling and the conversion to start based on using system with the similar mode of normal voice call.These principles of using the Packet data service that general purpose is provided in the TDMA cellular system will cause spectrum efficiency and performance unfavorable.

United States Patent (USP) 4916691 has been described a new group mode cellular radio system structure and transmission (speech and/or data) is divided into groups to the new process of mobile radio station.The public branch exchange and the honeycomb control unit of base station, process trunk interface unit link together through WAN.Process of transmitting is based on the conversion that mobile radio station begins and adds the identifier of the base station that (during calling out) this grouping is passed through for the title of any grouping that sends from mobile radio station.Under the situation from the time durations of the prolongation between the grouping of the user profile subsequently of mobile radio station, mobile radio station can send the extra control grouping of the purpose that is used to transmit the mesh positional information.

When the honeycomb control unit was distributed to a calling of this calling control number, it mainly participated in call establishment.It notifies mobile radio station and the trunk interface unit of this calling control number and the identifier of this base station of starting of this calling control number then.During calling out, be grouped in trunk interface unit and directly transmission between the serving base station at present.

The system of narration is not and provides the particular problem of Packet data service relevant in the TDMA cellular system in United States Patent (USP) 4916691.

At T Doc SMG 458/93 (1993.2.12) of ETSI (ETSI) " packet radio in GSM " be called the access protocol that may divide into groups that " for the general DPRS of GSM proposition " submitted to during the seminar of " GSM in following competitive environment " summarized speech and data in GSM in the new base in Finland Hull (1993.10.13) name.These files directly relate to the TDMA cellular system, i.e. GSM, though they have summarized may organizing of the shared Packet Data Channel optimized, they do not relate in the whole system solution aspect the comprehensive Packet Data Channel.

T Doc SMG 1 238/93, " grouped data in the GSM network " of ETSI (1993.9.28) described the notion that the Packet data service among the GSM is provided based on the pseudo channel between " agency " that at first use regular GSM signaling and checking foundation grouping mobile radio station and processing accessing group data business.Utilization is used for the regular signaling that modification was set up and discharged to Fast Channel, and then regular Traffic Channel is used for grouping and transmits.This file directly relates to the TDMA cellular system, but because this notion is based on the notion of " quick exchange " mode of using existing gsm service channel, with compare based on the notion of the shared Packet Data Channel of optimizing, it has the shortcoming of spectrum efficiency and grouping propagation delay (especially for short message).

Cellular Digital Packet Data (CDPD) systems technology standard 1.0 versions (1993.7) have been described the notion that Packet data service is provided, and it utilizes in present Advanced Mobile Phone Service (AMPS) system is the available radio channels of North America analog cellular system.CDPD is comprehensive, the open technical specification of being admitted by one group of U.S. honeycomb operator.The project that covers comprises external interface, air-link interface, business, network configuration, network management and management.

The cdpd system of regulation is based on and the irrelevant foundation structure of existing AMPS foundation structure to a great extent.With the AMPS system public be to be limited to the radio frequency channel of utilizing same type and identical base station site (base station of being used by CDPD may be new and special CDPD) and the signaling interface that adopts the channel allocation of coordination between two systems.

Send grouping and at first be based on this grouping of transmission to the home network node of equipping attaching position register (HLR) according to the address of mobile radio station (ownership mobile data intermediate system to mobile radio station, MD-IS), then when needs, according to HLR information send this grouping to visit, service MD-IS; Report that according to mobile radio station its mesh position sends the service MD-IS of this grouping to it through present base station from this service MD-IS at last.

Though the cdpd system technical specification does not directly relate to the particular problem that Packet data service is provided that is proposed by the application in the TDMA cellular system, network scenario of narrating in the cdpd system technical specification and notion can be used as the basis of the network facet of airlink protocols needs according to the present invention.

The CDPD network is designed to the extension of available data communication network and AMPS cellular network.Existing connectionless network protocol can be used for inserting the CDPD network.Because this network always is considered to form gradually, it uses an open network design, allows to increase new network layer protocol when appropriate.The network layer that CDPD Network and agreement are limited to osi model reaches with lower floor.Do to allow like this to need not to change following CDPD network than upper-layer protocol and application development.

From mobile subscriber's viewpoint, the CDPD network is the two the wireless mobile expansion of legacy network data and speech.Use the business of CDPD service supplier network, the user can seamlessly insert data and use, and many application may reside in traditional data network.Cdpd system can be regarded the service groups of two correlations as: the professional and CDPD Network of CDPD network support.

The professional required responsibility of maintenance and management CDPD network of carrying out of CDPD network support.These business are: accounting business; Network management system; Messaging delivery services; And authentication business.Define these professional mutual operation that generally allows between service supplier.Surpass its original AMPS structure because the CDPD network has comprised technically, can expect that this supporting business remains unchanged.The function of network support business is that any mobile network is necessary and irrelevant with radio frequency (RF) technology.

The CDPD Network is a data transport services, allows user and data application communication.In addition, the one or both ends of data communication can be moved.

In a word, according to the shared Packet Data Channel that grouped data is optimized is provided, need in the D-AMPS cellular system, provide a kind of system of the Packet data service of general objects.The application be at provide similar by the TIA/EIA/IS-136 standard code connection oriented network and the system and method for the advantageous combination of connectionless packet data network.

An importance in such system is channel or allocated bandwidth.An example of such channel allocation of IS-136 is to move auxiliary channel allocation (MACA).In IS-136, the Traffic Channel that typically sends the desired mobile radio station of transmission of MACA report on designated broadcast control channel (BCCH) receives the MACA report before.For example, carrying out based on connecting or can on fast B CCH, sending in the access parameter messages based on reserving the process of using in the access attempts.Such IS-136 random access parameter example comprises that very the busiest/reservation information, maximum retry information, maximum duplicate message and maximum stop counting.Because used the MACA report before assigned traffic channel, MACA does not provide any information after this mobile radio station inserts this system.

Another importance of cellular telephone communication system is balanced, and equilibrium is used for compensating the inhomogeneous or defective of radio medium.In order to reduce the purpose of multipath propagation influence, equalizer mainly is used in the receiving circuit, and reduces the influence of relative motion between the transmitter and receiver in cellular system.For example this narrates in WO88/05981, and it relates to the tdma system that comprises so-called adaptive equalization.The setting of equalizer of wireless receiver of packing into is to accompany or follow the synchronization character of the data word time multiplexing that transmitting set sends and decide.By these synchronization characters, equalizer can be set so that the diffusion attribute of compensation media.The wireless receiving that comprises equalizer through be usually used in high symbol rate communication (＞100kb/s), to the bit sensitivity of multipath propagation bit sensitivity greater than low character rate communication.A shortcoming using equalizer is complexity and the power consumption that they increase receiver.

Do not have equalizer that the advantage that can use non-coherent demodulation is provided, this causes the receiver complexity low lower with current drain.In addition, because high car speed, utilizing fast, the variation radio channel obtains firm receiver.Its shortcoming is that this demodulation can not disperse (timedispersion) to carry out with the time, and it constitutes the quite most of of symbol time.

According to one embodiment of present invention, the method for specifying mobile radio station new phase place in channel is again disclosed.In communication system, a plurality of mobile radio stations are attempted to communicate by letter on the channel of limited quantity.The present invention at first uses general distribution method so that the approximate mobile radio station that distributes on available channel equably.Begin after this system's efficient communication at mobile radio station, use second distribution method to change the phase place of some mobile radio stations on the channel that becomes heavy load.In addition, message also can send to mobile radio station, and this mobile radio station has been assigned to heavily utilized channel but has not also communicated by letter on heavily utilized channel effectively, refers to that former mobile radio station should change to new channel.

Read this specification in conjunction with the drawings and will understand the characteristic and the advantage of applicant's invention, wherein:

Fig. 1 schematically represents a plurality of the 3rd layer of message, second layer frame and ground floor channel pulse string or time slot;

Fig. 2 (a) represents a forward direction DCC, is configured to be included in a series of time slots in the continuous time slot that sends on the carrier frequency;

The example of Fig. 2 (b) expression IS-136 DCCH field time slot format;

Fig. 3 represents the classification of example or the cellular system of multilayer;

Fig. 4 is the block diagram of the cellular mobile telephone system of example, comprises the base station and the mobile radio station of an example;

An example of the order change that Fig. 5 expresses possibility;

Fig. 6 represents the PDCH example of appointment again;

Fig. 7 represents flow chart according to an embodiment of the invention;

Fig. 8 represents to receive the full rate mobile radio station of new phase place appointment; With

Fig. 9 represents to receive the mobile radio station of the Double Data Rate of new phase place appointment.

In order to help to understand the present invention, Fig. 5 illustrates the key diagram of a possible order change.Those skilled in the art is clear, the invention is not restricted to this order change, and is applied to other order change.Fig. 5 represents how a L3 message is transformed to the example of the packet dedicated digital control channel (PDCH) of several layer 2 frames, and layer 2 frame transforms to example on the time slot and time slot and transforms to example on the PDCH channel.The length of forward packet digital control channel (FPDCH) time slot and reverse packet digital control channel (RPHCH) pulse train is fixed, though the RPDCH pulse train of three patterns of different fixing length is arranged.Suppose that the FPDCH time slot is on the physical layer of Fig. 5.In the present invention, the tdma frame structure is identical with IS-136DCCH and DTC.For maximum throughput when using many speed rates (Double Data Rate PDCH and triple speed rate PDCH), stipulate an additional FPDCH time slot format.

Use the digital control channel (DCCH) of IS-136 to indicate the DDCH operation.Fig. 6 is illustrated in the DDCH (or more particularly, having public female DCCH) that belongs to a mesh and relation between the DCCH of different mesh (more particularly, being designated as the candidate of DCCH gravity treatment in the DCCH neighboar lists).Mobile radio station always at first arrives DCCH (female DCCH) when initial mesh is selected.At DCCH, indication is to the support of PDCH.If the DCCH indication provides a PDCH carrier frequency of (beacon PDCH) to the support of one or several special-purpose PDCH.Then in the Packet data service interested mobile radio station be tuned to beacon PDCH and read additional BCCH information so that determine whether to exist a plurality of PDCH.If there is more than one PDCH in the current business district, then mobile radio station is selected the PDCH of a PDCH as its appointment according to hashing algorithm.If this beacon PDCH is PDCH unique in the current business district, then it becomes the appointment PDCH of this mobile radio station.After determining the PDCH of its appointment, mobile radio station reads out in quick grouping BCCH (F-PBCCH) on the PDCH of its appointment and grouping BCCH (E-PBCCH) information of expanding.If necessary, mobile radio station is registered on the PDCH of its appointment according to PDCH mobile management rule subsequently.The PDCH registration can cause this mobile radio station to point to the appointment PDCH that substitutes or keep the PDCH of its present appointment.At this moment this mobile radio station also is activated for the Packet data service on the PDCH of its appointment except being activated for potentially the cellular services on its female DCCH.

In communication system, a plurality of mobile radio stations are attempted communicating by letter on the channel of limited quantity, and each channel can comprise a plurality of time slots.From the viewpoint of efficient, do not make all mobile radio stations be assigned to a channel, but they are dispersed in all channels is favourable.Narrate below and a phase assignments method shown in Figure 7.Therefore, after the PDCH of an appointment of initial selected, mobile radio station can advance on the PDCH of its appointment and register.In register response, distribute to available channel in real time for what mobile radio station was provided according to channel utilization (for example grouped data load), this service system can select to specify this mobile radio station to give a circuitous channel (for example appointment PDCH of Ti Daiing).Though the initial selected of the appointment PDCH that is undertaken by mobile radio station can be discerned (MSID or its last bit digital) according to mobile radio station and be provided at the original allocation of mobile radio station on the available channel, can carry out according to channel load or the mobile radio station of discerning in registration message attribute in the follow-up reallocation of record time.For example, move that can to indicate it be full rate, Double Data Rate or triple speed rate mobile radio station.Therefore, this system can think that a triple speed rate mobile radio station has and three potential loads that the full rate mobile radio station is identical when mobile radio station registration allocated channel.Therefore, because the mobile radio station of two triple speed rates has and six loads that the full rate mobile radio station is identical, this system can specify two triple speed rate mobile radio stations to give a channel when specifying six full rate mobile radio stations to give one other channel.

After mobile radio station was assigned to Packet Data Channel, this mobile radio station was in " wait for grouping " state, wherein this mobile radio station not with this system communication.In that " ' mobile radio station in the state is read all time slots except the time slot part to wait for grouping.In addition, mobile radio station may be in sleep pattern, and this mobile radio station short time wakes up regularly so that read single paging time-slot in this pattern.

Because for example the transmission capacity of mobile radio station and this channel of reception Capacity Ratio are little when the full rate mobile radio station is assigned to triple speed rate channel, this system and this mobile station communicate have problem.The full rate mobile radio station is intercepted one of three time slots only, and three possible phase places (time slot 1, time slot 2, time slot 3) are promptly arranged.For example, the full rate mobile radio station will only be intercepted a phase place of its allocated channel such as PPCH subchannel (PPCH-SUBCH).The Double Data Rate mobile radio station be operated in three may time slots two time slots ( time slot 1 and 2, time slot 2 and 3 and time slot 1 and 3).At last, triple speed rate mobile radio station is operated in all time slots, does not therefore need the rendezvous problem that solves.But to being operated in the mobile radio station of full rate and Double Data Rate, the phase place of mobile radio station and system (phase) must equate.Exist two activities that must solve this rendezvous problem: when this mobile radio station is in " waiting for grouping " state; With when this mobile radio station is in sleep pattern.

To being in the mobile radio station of sleep pattern, the present invention uses the full speed channel of channel to solve rendezvous problem at a predetermined phase paging mobile station, because all mobile radio stations must can be operated in full rate.For example, the paging of this system is in the mobile radio station of this channel first phase place.In addition, be included in that to get in many tdma frames that one specific paging time-slot can use may be that the identification of permanent mobile radio station of MIN or IMSI is determined.

Because several reasons, paging time-slot only is assigned to full speed channel.The first, compare with DCCH, less mobile radio station preemption PDCH is typically arranged.Even all mobile radio stations have grouped data ability and all users activated they the Packet data service account number this also be right because all PDCH mobile radio stations preempt DCCH after no activity on a large scale.The second, compare with the IS-136 operation, reduced the paging capacity that mobile radio station requires of preemption PDCH, because paging domain may be restricted to a mesh.At last, if use less chnnel coding, layer 2 frame is longer, can compare with the frame among the IS-136.This has strengthened the possibility that a plurality of pagings is grouped into single second layer frame, avoid in for example dispersion of paging on triple speed rate PDCH of all PDCH time slots, not should with the preemption PDCH the relevant too many paging time-slot of mobile radio station quantity.

When mobile radio station had been specified the PDCH channel rather than has been in sleep pattern, they read out in time slot on the FPDCH according to their ability.As a result, according to some parameters mobile radio station identifier for example, this mobile radio station can be assigned to out of phase equably.In addition, mobile radio station can determine to read which phase place (time of a subclass) according to the table 1 and 2 shown in following.

Table 1. mobile radio station PARCH phase assignments

	φ is calculated in mobile radio station PARCH channel usage (effective model)
The mobile radio station pattern				Full rate PDCH	Double Data Rate PDCH	Triple speed rate PDCH
Full rate	φ=undefined	φ=PPCH-SUBCH mould 2	φ=PPCH-SUBCH mould 3
Double Data Rate	Inapplicable	φ=undefined	φ=PPCH-SUBCH mould 3
The triple speed rate	Inapplicable	Inapplicable	φ=undefined

Table 2

	Mobile radio station PARCH phase place (effective model) the timeslot number number of finger (mould 4)
The mobile radio station pattern				Full rate PDCH	Double Data Rate PDCH	Triple speed rate PDCH
Full rate	All PDCH time slots	Master+φ	Master+φ
Double Data Rate	Inapplicable	All PDCH time slots	Master+φ and master+φ+1
The triple speed rate	Inapplicable	Inapplicable	All PDCH time slots

In sleep pattern or " wait for grouping " state the alternative solution of mobile radio station rendezvous problem be to mobile radio station send necessity in the enrollment response message synchronously.For example, register response can comprise speed and phase place message.In this replacement scheme, the PPCH subchannel needn't be got in touch with permanent mobile radio station identifier, and paging channel needn't be limited to full rate.In addition, the designated phase of the mobile radio station in " waiting for grouping " state also can provide in enrollment response message.

In case mobile radio station begins the efficient communication with this system, can heavily specify the phase place of this mobile radio station again, to proofread and correct any assignment problem that occurs in the above-mentioned general distribution method.In this embodiment, the 2nd layer of order can be used for notifying mobile radio station it should change its phase place, promptly mobile radio station is answered its phase place of sending and receiving of displacement.In this embodiment, do not change with the frequency (as channel number) of the mobile radio station of this system communication.Therefore, if there is too many mobile radio station on a certain channel, to send, then can only the phase place of displacement in this channel.But the 3rd layer of message can be used for telling mobile radio station also not begin communication, and they should be transformed into one other channel, make when they begin to communicate by letter, and they are not operated in overladen channel.As last replacement scheme, the definite single phase place of BCCH information that mobile radio station can always be served as reasons defaultly and be sent on FPDCH.Transmitting packetized digital information on the FPDCH to mobile radio station and any time during the process of RPDCH receiving block data information, this receiving system can be selected to revise phase place and specify.

The change of phase assignments influences forward direction and backward channel.For fear of the strict time restriction to mobile radio station, the permission mobile radio station keeps its current phase assignments to be used for the next scheduled transmission incident (time slot) of full rate transmission and is used for following two scheduled transmission incidents (two time slots) of Double Data Rate transmission.Fig. 8 and 9 expressions receive the full rate of new phase place appointment and the example of Double Data Rate mobile radio station.Shown in Fig. 8 and 9, after a complete frame, phase place occurs and specify again.

Though the present invention has so narrated, clearly may change in a lot of modes.Such variation does not think to break away from the spirit and scope of the present invention, and road as known in the art, and all such changes are predetermined to be included in the scope of following claims.

Claims (9)

1. method of distributing mobile radio station phase place in the channel in the communication system comprises step:

Before or after registration, in available channel, distribute mobile radio station, so as described mobile radio station begin with this system communication before approximate distribute described mobile radio station equably;

Specify mobile radio station to the interior predetermined phase of their channel appointed; With

Reassign mobile radio station and give out of phase in their allocated channels, in case reallocation mobile radio station when this mobile radio station begins with this system communication.

2. according to the process of claim 1 wherein that described mobile radio station distributes the attribute that is based on mobile radio station.

3. according to the process of claim 1 wherein that the distribution of described each mobile radio station is based on mobile radio station identification.

Therefore 4. according to the process of claim 1 wherein that some described mobile radio stations are in sleep pattern after registration, and has the minimum bandwidth communication path that utilizes this system's activation.

According to the process of claim 1 wherein with this system registration after some mobile radio stations reading all time slots, and therefore have the maximum bandwidth communication path that utilizes this system's activation.

6. according to the process of claim 1 wherein that described phase place is relevant with the time slot in the tdma frame.

7. base station comprises:

A processor, the initial phase that is used to prepare mobile radio station specifies the phase place of first relevant message and change to specify the second relevant message; With

A transmitter is used to send described first message and second message to described mobile radio station.

8. according to the base station of claim 7, wherein said second message is produced by described processor, so that distribute the load of described mobile radio station more equably in channel.

9. according to the base station of claim 7, wherein, send described first message by described transmitter after described mobile radio station receives registration message.

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