CN1745600A - Forward link handoff for wireless communication systems with OFDM forward link and CDMA reverse link - Google Patents
Forward link handoff for wireless communication systems with OFDM forward link and CDMA reverse link Download PDFInfo
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Abstract
A method and apparatus for performing handoff in a wireless communication system with multi-carrier modulation (MCM) for a forward link and CDMA for a reverse link. In one embodiment, a method of performing handoff on the forward link for a terminal is provided in which signal quality of pilots received by the terminal from a plurality of base stations in the system is determined. A particular base station for subsequent data transmission on the forward link to the terminal is selected based on the signal quality determined for the plurality of base stations. A request to be handed off to the particular base station is initiated if the particular base station is different than a currently selected base station.
Description
Require the priority under 35 sections 119 in U.S.
The application requires the 60/438th, No. 666 of submission on January 7th, 2003, and title is the priority of the provisional application of " forward link handoff in the wireless communication system of use OFDM forward link and CDMA reverse link ".
Technical field
The present invention relates generally to data communication, relate more specifically to be used for carrying out on the forward link of wireless communication system the technology of handover, this wireless communication system uses multi-carrier modulation (for example OFDM) on the forward link and use CDMA on reverse link.
Background technology
Wireless communication system is widely used in providing multiple communication, for example voice, grouped data or the like.These systems can support multiple access system with multi-user communication by sharing the available system resource.This system can be based on code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), some other multiple access technique, perhaps their combination.Cdma system also can be designed as some well-known CDMA standards, for example cdma2000, IS-856, IS-95, W-CDMA and other standard carried out.
In direct sequence (DS) cdma system, narrow band signal is expanded on the whole system bandwidth on the time domain with a frequency expansion sequence.Some examples of this DS-CDMA system comprise those systems that carry out IS-2000, IS-95 and W-CDMA standard.Frequency expansion sequence can be pseudo-random number sequence (for example being used for IS-95 and IS-2000) or scramble sequence (for example being used for W-CDMA).The DS-CDMA system provides some advantage, for example is easy to support multichannel access, arrowband inhibition etc.
OFDM (OFDM) is divided into system bandwidth the subband of many (N) individual quadrature effectively, and subband is also referred to as tone, frequency band (frequency bin) usually, and frequency subchannels.In every period time interval of the bandwidth that depends on each subband, modulation symbol can be transmitted on each of N subband.OFDM can be used to prevent intersymbol interference (ISI), and intersymbol interference is that each character in the signal that has received all works to the character of its back in this signal and causes the phenomenon of its distortion thus.ISI is caused by the decline of the selectivity of the frequency in the multiplex (MUX).For preventing intersymbol interference, as well known in the art, the part of each OFDM symbol was repeated to send before transmission.
Owing to multiple reason, a kind of communication link uses a kind of modulation technique (for example in forward link OFDM technology) and complementary communication link uses another kind of modulation technique (for example in the reverse link CDMA technology) more favourable.But the use of multiple modulation technique may make some system operation complicated, the handover of the terminal between each base station in for example a plurality of systems.
Therefore this area exists a kind of demand, promptly needs a kind of technology that is used for carrying out handover on the forward link of mixed wireless communications system.
Description of drawings
Fig. 1 is a wireless communication system;
Fig. 2 is the flow chart of an embodiment of carrying out the forward link handoff process of starting terminal;
Fig. 3 is a flow chart of carrying out an embodiment of the forward link handoff process that BTS starts;
Fig. 4 is the block diagram of an embodiment of base station and terminal.
Embodiment
" demonstration " this speech refers to " explanation as an example, for example, " here.Here being called as the embodiment and the design of " demonstration " and not meaning that must be more superior or favourable than other embodiment and design.
Fig. 1 shows a wireless communication system 100 can carrying out forward link handoff technology mentioned in this article.Comprise a plurality of base stations in the system 100, each base station covers the corresponding geographical zone.For easy, Fig. 1 only shows 110a, 110b and three base stations of 110c.The base station also can be called as access point, Node B, perhaps other term.Depend on the context that this speech occurs, base station and/or its overlay area are also referred to as the sub-district usually.Be the increase capacity, the overlay area of each base station can be divided into a plurality of sectors.Each sector provides service by relevant base station transceiver subsystem (BTS).For one by the sub-district of sectorization, each sector that the base station of this sub-district can be included as this sub-district provides all BTS of service.For easy, following explanation supposes that each sub-district is divided into three sectors, and these three sectors provide service by three BTS that are positioned at the base station, and three BTS are located at the center of this sub-district successively.
Multiple terminal is typically distributing in the whole system.For easy, Fig. 1 only shows a terminal 120.Terminal also can be described as remote work station, travelling carriage, access terminal, subscriber equipment (UE), Wireless Telecom Equipment, perhaps other term.Can communicate with one or more BTS on the forward link or the one or more BTS on the reverse link in any each terminal of given time.This depends on whether this terminal works, whether transfer of data supports soft handover, whether this terminal at soft handoff state.Forward link (down link just) is meant the communication link from BTS to the terminal, and reverse link (up link just) is meant the communication link from the terminal to BTS.
For example, system controller 102 is connected on the base station 110 and can be further be connected with other system such as public switched telephone network (PSTN), Packet Data Network (PDN) etc.System controller 102 also can be called as base station controller (BSC), radio network controller (RNC), perhaps other term.102 pairs of coupled base stations of system controller are coordinated and are controlled.System controller 102 is further controlled the terminal of the route of the calling between each terminal of (1) system 100 and (2) system 100 and is connected to the route of the calling between other user of other system (for example PSTN) via this base station.
For simplified system designs and improve the throughput of whole system, system 100 can be designed as and supports soft handover (SHO) and do not support in forward link in reverse link.By from a plurality of BTS to a terminal transmission redundant data to increase reliability of data transmission, obtain the soft handover on the forward link.But the redundancy in the forward link transmissions also can reduce power system capacity.
By making a plurality of BTS that are arranged in identical or different sub-district receive and handle the reverse link signal of self terminal, obtain the soft handover on the reverse link.If these a plurality of BTS serve a plurality of sectors in the same sub-district, the reverse link signal combination (is commonly called " softer handover " process (softerhandoff)) that comes self terminal that then before decoding, these BTS can be received.If these a plurality of BTS serve a plurality of sectors in the different districts, then each BTS can carry out independent process and decoding to the signal that receives from terminal, selects decoded data for one that system can be from these BTS then.In any case the soft handover on the reverse link can increase to the capacity that cost improves the reliability of rl transmission and further increases whole system with the signal processing amount of a plurality of BTS.Do not allow the data user to use some examples of the cdma system of soft handover to comprise (1) IS-856 system in forward link, be also referred to as the 1xEV-DO system, (2) IS-2000 system is also referred to as the 1xEV-DV system, and (3) W-CDMA system.
Each BTS passes to each terminal to data by forward link in its sector.Each BTS pilot signal transmitted on the forward link also in addition, this pilot signal can be positioned at each inside and outside terminal of this sector and receive and identify.If do not use soft handover in the forward link, then only receive the transmission of user's data designated from a BTS in any each active terminal of given time, this often is called as serving sector.When the serving sector of a terminal changes, hard handoff will take place on the forward link switch (perhaps being called for short handover).
1, forward link pilot signal
Each BTS sends a pilot signal (perhaps abbreviating " OFDM pilot signal " as) on the OFDM forward link, this pilot signal can be by terminal as multiple function, and for example channel estimating, timing and frequency are obtained, the power measurement of coherence data demodulation, received signal or the like.The detection that the OFDM pilot signal of BTS emission can improve each terminal of system in some sense.
Each BTS can be set to send its pilot signal on one group of specific subband.Contiguous BTS can be assigned to and different disjointly respectively organize subband so that their pilot signal mutually orthogonal in frequency domain.The pilot signal of each BTS can further be assigned to the specific orthogonal code mask (cover) of this BTS.Near BTS (for example distributing to those BTS of same group of subband) can be assigned with different orthogonal codes so that their pilot signal at the time-domain mutually orthogonal.The terminal of the orthogonality of the pilot signal in frequency domain and/or time domain in can the raising system is to the detection of these pilot signals and catch.
The OFDM pilot signal of each BTS can further be carried out scrambling with the specific scrambler of distributing to this BTS.Scrambler makes the terminal in pilot signal interference randomization and the further permission system discern each BTS uniquely based on the pilot signal that receives.
It is 10/359 that the various pilot transmission scheme that can be applicable to the OFDM forward link are recorded in the application number of submitting on February 7th, 2003,811, title is the U.S. Patent application of " pilot transmission scheme that is used for wireless multi-carrier communication system ", it transfers assignee of the present invention, is hereby expressly incorporated by reference.
2, the forward link handoff of starting terminal
A terminal of system can be constantly or is periodically monitored the forward link transmissions of sending from each BTS of system and judge and select which BTS as serving sector.In one embodiment, the selection of the serving sector power measurement that is based on the pilot signal that receives from BTS is made.Usually, can be based on any measurement of BTS signal quality, for example, signal to noise ratio (snr) is made the selection to serving sector.
Fig. 2 shows a flow chart of carrying out an embodiment of terminal-initiated forward link handover procedure 200.Process 200 can be carried out by terminal.
The power (step 212) of the OFDM pilot signal that receives from a plurality of BTS is measured in beginning, terminal.Terminal has the knowledge that receives the relevant information required with handling the OFDM pilot signal sent from the BTS of different sectors.These information depend on the specific pilot transmission scheme that system carries out.For above-mentioned application number is 10/359, the pilot transmission scheme of describing in 811 the U.S. Patent application, these information can comprise, for example, be used for that group subband of each BTS of pilot signal transmission, each BTS is used for covering its pilot signal before transmission orthogonal code (for example walsh code), and each BTS is used for its pilot signal of scrambling to realize BTS identification and randomized scrambler.It can be that the method for 10/359,811 U.S. Patent application is carried out according to above-mentioned application number that the pilot signal of being undertaken by terminal is handled.The output that pilot signal is handled is the pilot signal power of the measurement of each BTS of receiving of terminal.Then with the pilot signal power ordering (for example according to descending sort) (step 214) of the measurement of the BTS that receives.
A special case, if there is the subband of 512 OFDM forward links in system, nearly 10 in these subbands (for example, 50 subbands, subscript is respectively 10,20,30 ... 500) can be used as pilot subbands.Terminal can be measured the power of the pilot signal that receives on each subband in these pilot subbands and further to the average pilot signal power of the measurement that obtains BTS of the pilot signal power on these 50 pilot subbands.The function of the pilot signal power that usually, receives or the signal to noise ratio of pilot subbands can be used for the selection of serving sector.
Choose the serving sector (step 216) of the follow-up forward link data transmission of terminal then.Selection to serving sector is based on pilot signal power and (2) specific selection algorithms of the measurement of each BTS that (1) receive.Hysteresis during this algorithm can utilize and select handle avoids two table tennises between the serving sector to switch (that is, asking continually to change) between two approaching sectors of the pilot signal power that is received by terminal or signal to noise ratio.Hysteresis can be carried out by using different switching levels and timer or other mechanical device.For example, have only the pilot signal power some that has surpassed the measurement of current service sector when the pilot signal power of the measurement of this sector, terminal just can ask to be handed over to another serving sector.
Judge the new serving sector of selecting and current service sector whether identical (step 218) then.If the serving sector of this new selection is identical with the current service sector, then this process is got back to step 212.Otherwise terminal is sent hand-off request to selected serving sector, and the pilot signal power that this selecteed serving sector receives surpasses current service sector (step 220).Except hand-off request, terminal also can be sent other relevant information, for example, terminal estimate can successful demodulation maximum data rate.
For the hand-off request that receives from terminal, system can permit or refuse this request.This decision is based on that different factors as described below make.If hand-off request is licensed, then this permission will be informed terminal with signal form, follow new serving sector and send data by forward link to terminal.Otherwise terminal can continue from current service sector reception forward link data transmission.
To consider various factors/criteria in decision permission when still refusal is from hand-off request that terminal is sent.To the serving sector of terminal preferably to select not be must be the sector that the OFDM pilot signal power is the strongest or signal to noise ratio is maximum that terminal receives.Other factors also will be considered, and comprise the load capacity of this sector, every reverse link measurement that BTS makes terminal, the priority of terminal, the current service that obtains of terminal or the like.For example, the sector with forward link of low load is than high capacity forward link sector better choice, particularly when the difference of the pilot signal power of the measurement of these two sectors or signal to noise ratio is very little.Like this based on the cognition to the forward link loading condition of these BTS, the BTS of current service sector just can permit or refuse the handover application transmitted from terminal.
3, the forward link handoff of BTS startup
Based on the rl transmission of coming self terminal, forward link handoff also can be started by BTS.Based on the power of the reverse link pilot that receives from terminal or the measurement of signal to noise ratio, BTS can make forward link handoff and select.
Fig. 3 shows an embodiment flow chart that is used for carrying out the processing 300 of the forward link handoff that BTS starts.Handling 300 can be carried out by system.
Beginning, a plurality of BTS in the system measure the power (step 312) of the reverse link pilot that receives from terminal.For example, if terminal is sent pilot signal on the CDMA reverse link, then carry out despreading, remove mask (decovering) and add up by the reverse link pilot to coming self terminal of using CDMA pilot signal filter, each BTS can judge the average power of the pilot signal that receives from terminal.The processing of CDMA reverse link pilot is well-known in this area, no longer describes in detail here.The output that pilot signal is handled is the pilot signal power from the measurement of the BTS of terminal reception pilot signal.
Next be forward link data transmission selection serving sector (step 316) afterwards to terminal.It is to carry out from each BTS that terminal receives reverse link pilot by coordination that serving sector is selected.These BTS can unite which sector of judgement should be served terminal on the OFDM forward link.This serving sector selects to be based on that the power of the pilot signal that BTS measures and specific selection algorithm carry out, this algorithm can be identical with the algorithm of the forward link handoff of the used starting terminal of terminal also can be different.In addition, hysteresis can be used to avoid two table tennises between the serving sector to switch.
Judge then whether the serving sector of the new selection of terminal is same as the current service sector (step 318) of terminal.If the new serving sector of selecting is identical with the current service sector, then handles and get back to step 312.Otherwise it is handed over to new serving sector (step 320) can to send signaling to terminal.
With in like manner top, preferably the selecting of the serving sector of terminal not necessarily has the sector of the reverse link pilot power of the terminal that maximum receives.For example, the sector of a low loaded forward link of selection is a better choice than the sector of high capacity forward link, particularly under the very little situation of the difference between the power of being measured by these sectors that receives.Therefore these BTS will consider load and other relevant information when forward link handoff of decision startup changes the serving sector of this terminal.
4, the performance of forward link handoff
The forward link handoff of starting terminal can provide the forward link handoff more performance that starts than BTS.At first, because the selection of serving sector is based on the measurement on the OFDM forward link, so the handover of starting terminal can be more accurate.What on the contrary, the handover that starts of BTS was based on reverse link respectively measures and depends on average forward link and the correlation between the reverse chain channel.Secondly, the handover of starting terminal can be activated quickly than the handover that BTS starts.This is because the decision of handover is to be made based on the forward link measurement from a plurality of BTS by terminal.On the contrary, the handover of the handover that BTS starts decision is based on from the measurement on a plurality of BTS of a terminal and makes, and can cause the delay of some processing and transmission.
The optimality that serving sector is selected in the handover of starting terminal depends on the accuracy of the BTS power measurement that receives.The optimality that serving sector is selected in the handover that BTS starts depends on accuracy and the forward link of (2) OFDM modulation and the correlation or the coherence between the CDMA reverse link of (1) BTS power measurement.The degree that this forward/reverse link is relevant depends on the relevant degree between reverse link and the forward link decline process.If satisfy one of following two conditions, this decline correlation can be quite little: (1) forward direction and reverse link be transmitted on the different frequency bands and these two frequency bands between very big or (2) wireless channel in interval very big delay expansion is arranged.But the average characteristics of forward direction and reverse link should be similarly (based on the consideration in area), even these links experience incoherent decline process when coherence bandwidth (providing with the inverse that postpones expansion) is littler than two band separations.
Like this, terminal can ask forward link handoff to change its serving sector, and the OFDM pilot signal that the determining to be based on of serving sector receives by the forward link from a plurality of BTS is in the measurement of terminal.Based on load on the forward link of each sector and the getable relevant information of other BTS, the BTS on the serving sector can permit or refuse hand-off request.Can be used on the forward link depending on the quality of the wireless channel between selecteed serving sector and the terminal to the data transfer rate of the transfer of data of terminal.The forward link handoff that the forward link handoff that BTS starts can be used for combining with the forward link handoff of starting terminal or replacement terminal starts.
5, system
Fig. 4 shows a base station 110x in the system 100 and the embodiment block diagram of terminal 120x.For illustrative ease, base station 110x only handles a sector.
By forward link,, send (TX) data processor 414 and receive from the traffic data of data source 412 and signaling and other data of coming self-controller 430 at base station 110x.414 pairs of data of TX data processor format, encode, interweave and modulate (be character mapping) so that data modulation symbol to be provided, perhaps be referred to as data symbol simply.The processing that modulator (MOD) 420 receives and multiplex data symbol and frequency pilot sign, execution are required also provides OFDM symbols streams.The application number of being mentioned in front by the processing of modulator 420 is to state in 10/359,811 the U.S. Patent application.Next transmitting element (TMTR) 422 is handled the OFDM symbols streams so that a forward link signal to be provided, and this signal is transmitted into each terminal from antenna 424.
At terminal 120x, the forward link signal that is sent by a plurality of base stations of a plurality of sectors is received by antenna 452, the signal that is received is handled (for example, amplification, filtering, down-conversion and digitlization) so that sample to be provided by a receiving element (RCVR) 454.Demodulator (DEMOD) 460 handling sample for the method that is capped the method complementation of being adopted when the sector provides measurement pilot signals power and data symbol to estimate with modulator 420 with a kind of.Receiving (RX) data processor 462 further handles (for example, the symbol reflection is penetrated, deinterleaving and decoding) data symbol and estimates that decoded data can and/or supply controller 470 do further processing for data sink 464 storages so that decoded data to be provided.
Processing to reverse link can be carried out according to the CDMA standard or to the design that reverse link is implemented.Data and signaling are handled (for example, encode, interweave and modulate) to produce data symbol by TX data processor 484, and data symbol is further handled to produce with the multiplexing and modulated device 490 of pilot signal sign indicating number sends symbol.Transmitting element 492 is further handled to generate reverse link signal sending symbol, and this signal is launched from antenna 452.
At base station 110x, the reverse link signal of sending from terminal is received by antenna 424, and the signal that is received is received unit 438 and handles so that sample to be provided.Sample is further handled to provide data symbol to estimate by demodulator 440, and this data symbol estimates that being done further processing by RX data processor 442 to provide decoded data for each terminal that is covered again.Decoded data can be done further processing for data sink 444 storages and/or for controller 430.
Controller 430 and 470 is controlled the operation of base station and each processor of terminal respectively.Memory cell 432 and 472 is stored data and controller 430 and 470 employed program codes respectively.Controller 470 is carried out processing procedure shown in Figure 2 and is determined whether starting a hand-off request.If another sector is received better than current service sector, controller 470 will for TX data processor 484 provide one can be for the message of hand-off request of the BTS that is transferred to the current service sector.The controller 430 of each BTS can participate in the handover that processing shown in Figure 3 determines whether starting a terminal.A plurality of controllers of a plurality of BTS can co-ordination be carried out the forward link handoff that the BTS of terminal starts.
Forward link handoff technology described here can be carried out in many ways.For example, these technology can with hardware, software or it be in conjunction with realizing.Realize for hardware, each element that is used to be supported in the forward link handoff on BTS and the terminal can and be other designed electronic device of execution function as described herein at one or more application-specific integrated circuit (ASIC)s (ASIC), digital signal processor (DSP), digital signal processing appts (DSPD), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, and perhaps their combination realizes.
Realize that for software the module of some function of execution that forward link handoff technology described here can be mentioned (for example, step, function or the like) is carried out here.Software code can be stored in the memory cell (for example, the memory cell among Fig. 4 432 and 472) and by processor (for example controller 430 and 470) and carry out.Memory cell can also can be in the outside of processor in processor inside, and externally memory cell can be directly connected on the processor by any known method in this area under the situation.
The title that this paper comprises is to be used for reference and to be used for locating particular sections.These titles are not in order to limit the scope of the following notion of this paper, and these notions may also be suitable in the other parts of whole specification.
Above-mentioned disclosed embodiment is that any professional and technical personnel who supplies with this area realizes or use the present invention.The various modifications of these embodiment are conspicuous for those skilled in the art, and Ding Yi General Principle can be applied to other embodiment and not deviate from the spirit or scope of the present invention here.Therefore, the present invention is not limited among these embodiment shown in this paper but the widest range that conforms to novelty with principle disclosed herein is consistent.
Claims (15)
1. one kind is used multi-carrier modulation (MCM) on the forward link and uses on reverse link in the wireless communication system of CDMA, and terminal is carried out the method for the handover on the forward link, comprising:
Judge the signal quality of the pilot signal that a plurality of base stations of described terminal from system receive;
Based on the described signal quality that a plurality of base stations are judged, for the subsequent data transmission to the forward link of described terminal is selected specific base stations;
If described specific base stations is different with the current base station of having selected, then start request to described specific base stations handover.
2. according to the described method of claim 1, wherein said multi-carrier modulation is OFDM (OFDM).
3. according to the described method of claim 1, wherein said signal quality is relevant with pilot signal power.
4. according to the described method of claim 1, wherein said signal quality is relevant with signal to noise ratio (snr).
5. according to the described method of claim 1, wherein said selection is also based at least one additional criteria.
6. according to the described method of claim 5, the load in wherein said at least one additional criteria and the system on the forward link of base station is relevant.
7. according to the described method of claim 1, wherein said selection is to utilize hysteresis to prevent that two table tennises between the base station from switching and carry out.
8. one kind is used multi-carrier modulation (MCM) on the forward link and uses in the wireless communication system of CDMA at reverse link, and terminal is carried out the method for the handover on the forward link, comprising:
The quality of signals that judgement is received from described terminal by a plurality of base stations in the system;
Based on the described signal quality of judging by a plurality of base stations, for the subsequent data transmission on the forward link of described terminal is selected specific base stations;
Start the handover of described terminal to described specific base stations.
9. according to the described method of claim 8, wherein said multi-carrier modulation is OFDM (OFDM).
10. according to the described method of claim 8, wherein said signal quality is relevant with pilot signal power.
11. according to the described method of claim 8, wherein said selection is further based at least one additional criteria.
12. according to the described method of claim 11, the load in wherein said at least one additional criteria and the system on the forward link of base station is relevant.
13. according to the described method of claim 11, wherein said at least one additional criteria and a plurality of base stations are relevant from the measurement of the signal that terminal receives.
14. one kind is used multi-carrier modulation (MCM) on the forward link and use terminal in the wireless communication system of CDMA on reverse link, comprising:
Judge the device of the pilot signal quality that a plurality of base stations of described terminal from system are received;
Based on the described signal quality that a plurality of base stations are judged, select the device of specific base stations for the subsequent data transmission to the forward link of described terminal;
If described specific base stations is different with the current base station of having selected, then start device to described certain base station hand-off request.
15. one kind is used multi-carrier modulation (MCM) on the forward link and use equipment in the wireless communication system of CDMA on reverse link, comprising:
The device of the quality of signals that judgement is received from described terminal by a plurality of base stations in the system;
Based on the described signal quality of judging by a plurality of base stations, select the device of specific base stations for the subsequent data transmission on the forward link of described terminal;
Start the device of described terminal to the handover of described specific base stations.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US43866603P | 2003-01-07 | 2003-01-07 | |
| US60/438,666 | 2003-01-07 | ||
| US10/744,373 | 2003-12-22 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510118845.5A Division CN104661271A (en) | 2003-01-07 | 2004-01-07 | Method and device of performing handoff on forward link for terminal |
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| Publication Number | Publication Date |
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| CN1745600A true CN1745600A (en) | 2006-03-08 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200480003115 Pending CN1745600A (en) | 2003-01-07 | 2004-01-07 | Forward link handoff for wireless communication systems with OFDM forward link and CDMA reverse link |
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| CN (1) | CN1745600A (en) |
| TW (1) | TW200503494A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101141793B (en) * | 2006-09-08 | 2010-12-08 | 华为技术有限公司 | Switch judging method of mobile communication service and mobile communication system |
| CN101932017A (en) * | 2009-06-19 | 2010-12-29 | 美商威睿电通公司 | Load balancing management with and the device for mobile communication, the method and system that are suitable for |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4440831B2 (en) * | 2005-06-14 | 2010-03-24 | 株式会社エヌ・ティ・ティ・ドコモ | Base station apparatus, transmission method, and communication system |
-
2004
- 2004-01-06 TW TW093100232A patent/TW200503494A/en unknown
- 2004-01-07 CN CN 200480003115 patent/CN1745600A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101141793B (en) * | 2006-09-08 | 2010-12-08 | 华为技术有限公司 | Switch judging method of mobile communication service and mobile communication system |
| CN101932017A (en) * | 2009-06-19 | 2010-12-29 | 美商威睿电通公司 | Load balancing management with and the device for mobile communication, the method and system that are suitable for |
Also Published As
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|---|---|
| TW200503494A (en) | 2005-01-16 |
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