CN101395953A - Method and apparatus for searching radio technologies - Google Patents

Abstract

Techniques to improve searches for wireless networks are described. A terminal uses results of a search for one radio technology to reduce the search space for another search for the same radio technology or a different radio technology. In one scheme, a first search for a first radio technology (e.g., GSM) is initially performed, and search results indicating frequency channels acquired for the first radio technology are obtained. A second search for a second radio technology (e.g., W-CDMA) is performed using the results of the first search to omit frequencies from the second search. In another scheme, acquisition is performed on at least one frequency channel previously acquired for a radio technology (e.g., W-CDMA). A search for the radio technology is then performed using results of the acquisition to omit frequencies from the search.

Description

The method and apparatus that is used for searching radio technologies

Background

Related application

The application requires the U.S. Provisional Application No.60/780 of submission on March 7th, 2006,270 priority.

I. field

The disclosure relates generally to communication, relates in particular to the skill and technique that is used for searching radio technologies.

II. background

Cordless communication network is disposed widely to provide such as various communication services such as voice, grouped data, broadcasting, information receivings.These wireless networks can be supported communication for the multi-user by sharing available network resource.The example of this type of wireless network comprises code division multiple access (CDMA) network, time division multiple access (TDMA) network and frequency division multiple access (FDMA) network.These wireless networks also can adopt known in the art such as broadband-CDMA (W-CDMA), cdma2000, global system for mobile communications various radiotechnicss such as (GSM).

Terminal can with communicate by letter with the different networks of GSM network such as W-CDMA.Terminal can be carried out search to seek the wireless network that this terminal can obtain service from it.Terminal can at first be searched for a frequency band (for example to seek the specific wireless power technology, W-CDMA) wireless network, (for example, wireless network GSM) generates the tabulation of all wireless networks that find by these search then to seek another radiotechnics then identical frequency band to be carried out another search.Search to each radiotechnics may be consuming time, for example, for having the crowded frequency band that many wireless networks work just therein be minute magnitude on.May cause excessive delay being arranged as a result the time long search time at search report.

Therefore, there is demand in this area to improved search to cordless communication network.

General introduction

The skill and technique that is used to improve to the search of wireless network has been described herein.In general, terminal can use result at a kind of search of radiotechnics to come to be another search reduction search volume at same wireless power technology or different radio power technology.

In one embodiment, the initial execution at (for example, first search GSM), and obtain to be designated as the Search Results of the frequency channels that this first radiotechnics catches of first radiotechnics.Subsequently, use result of this first search to carry out that (for example, second search W-CDMA) is to save frequency from second search at second radiotechnics.For example, second search can be saved in the frequency of scope on every side that is first radiotechnics each frequency channels of successfully catching.

In another embodiment, formerly be that radiotechnics (is carried out at least one frequency channels of for example, W-CDMA) catching and caught.Use the result of this seizure to carry out search at this radiotechnics subsequently to save frequency from search.The frequency of being saved can comprise the centre frequency of each frequency channels that does not successfully catch (1); And the frequency of the scope of (2) each frequency channels of successfully catching.

At following various aspects of the present invention and the embodiment of describing in further detail.

The accompanying drawing summary

Understand the detailed description of setting forth below in conjunction with the accompanying drawings, it is more apparent that various aspects of the present invention and embodiment will become, and identical in the accompanying drawings Reference numeral is carried throughout and made respective identification.

Fig. 1 shows the deployment with GSM network and Universal Mobile Telecommunications System (UMTS) network.

Fig. 2 shows the protocol layer of GSM and UMTS.

Fig. 3 shows the manual search process.

Fig. 4 shows the thick and thin frequency scanning at UMTS.

Fig. 5 shows the frequency of saving based on the GSM Search Results.

Fig. 6 shows the manual search process at GSM and UMTS.

Fig. 7 shows the frequency of saving based on the acquisition database Search Results.

Fig. 8 shows the search procedure that has the acquisition database search.

Fig. 9 shows the automatic search procedure at GSM and UMTS.

Figure 10 shows the search procedure that is used for the service that obtains from wireless network.

Figure 11 shows the search procedure at multiple radiotechnics.

Figure 12 shows the search procedure at radiotechnics.

Figure 13 shows the block diagram of terminal.

Describe in detail

Word " exemplary " is used for expression " as example, example or illustration " in this article.In this any embodiment or design that is described to " exemplary " all is not must be interpreted to be better than or to surpass other embodiment or design.

Search skill and technique described here can be used for various cordless communication networks, such as UMTS network, GSM network, cdma2000 network etc.Term " network " and " system " are used usually interchangeably.The GSM network uses GSM to air interface, and core net is used MAP (MAP).The UMTS network uses W-CDMA to air interface, and core net is used MAP.Term " air interface ", " radiotechnics " and " radio access technologies " are used usually interchangeably.Term " W-CDMA " and " UMTS " are also used usually interchangeably.GSM can provide voice service and low speed to arrive the second generation (2G) radiotechnics of middling speed packet data service.W-CDMA can provide for example third generation (3G) radiotechnics of enhanced service such as higher data, concurrent voice and data call and ability.GSM and W-CDMA describe in the available document of the public from the tissue that is called " third generation partner program (3GPP) ".Generally speaking, wireless network can use such as any radiotechnicss such as W-CDMA, GSM, cdma2000 or other certain radiotechnicss.Virtual network operator/service provider can dispose one or more wireless networks of one or more radiotechnicss.For the purpose of distinct, below the search skill and technique is described with regard to GSM and UMTS.

Fig. 1 shows the deployment 100 that comprises GSM network 110 and UMTS network 120.GSM network 110 comprises the base station 112 with terminal communication in the area of coverage of GSM network.The base station is with the fixed station of terminal communication and also can be described as B node, basic transceiver station (BTS), access point etc.Mobile switching centre (MSC) 114 is coupled to base station 112 and coordinates and control for these base stations provide.UMTS network 120 comprises the base station 122 with terminal communication in the area of coverage of this UMTS network.Radio network controller (RNC) 124 is coupled to base station 122 and coordinates and control for these base stations provide.RNC 124 can communicate by letter with MSC 114 to support the intercommunication between UMTS and the GSM network.Wireless network typically comprises many cellular cells, and wherein term " cellular cell " depends on that the context that uses this term can refer to the area of coverage of base station or base station.In the following description, base station 112 is also referred to as the GSM cellular cell, and base station 122 is also referred to as the UMTS cellular cell.

Multimode terminal 150 (for example, dual-mode cellular telephone) can be communicated by letter with UMTS network 120 with GSM network 110, typically at any given time and a wireless communication.This ability allows the user to obtain the performance advantage of W-CDMA and the covering benifit of GSM with same terminal.Terminal 150 can be fixing or move, and also can be described as subscriber's installation (UE), mobile radio station (MS), mobile equipment (ME) etc.Terminal 150 can be cell phone, PDA(Personal Digital Assistant), radio modem, Wireless Telecom Equipment, subscriber unit, wireless laptop computers etc.

GSM network 110 and UMTS network 120 can be included into identical or different public land mobile network (PLMN).PLMN can comprise one or more wireless networks, for example, and one or more GSM networks and/or one or more UMTS network.PLMN comes uniqueness ground sign by specific mobile country code (MCC) and specific mobile network code, MNC (MNC).The UMTS network of given PLMN and GSM network can have overlapping or nonoverlapping area of coverage.In given geographic area, also can dispose a plurality of PLMN by different service providers.

But terminal 150 can have the tabulation that this terminal can receive the preferred PLMN of service from it in advance.This preference lists can be prepared to the service provider of its subscription by terminal 150.Preference lists generally includes Home PLMN (HPLMN) and the service provider has other PLMN of roaming agreement to it.Preference lists can be stored in subscriber identity module (SIM), general SIM (USIM) or other certain non-volatile memory module.Terminal 150 also can be safeguarded the tabulation of the PLMN that obtained of searching period formerly of this terminal.The tabulation that obtains PLMN can be stored in the acquisition database in the nonvolatile memory.

PLMN can work on one or more frequency bands.Each wireless network in each PLMN is typically worked on the one or more certain frequency channel in special frequency band.Table 1 has been listed and has been GSM and the shared frequency band of UMTS network.

Table 1

Frequency band	Frequency band	Up link (MHz)	Down link (MHz)	Common first names
						UMTS frequency band I	1920-1980	2110-2170	IMT-2000
GSM?1900	UMTS frequency band II	1850-1910	1930-1990	PCS
					GSM?1800	UMTS frequency band III	1710-1785	1805-1880	DCS
	UMTS frequency band IV	1710-1770	2110-2170
					GSM?850	UMTS frequency band V	824-849	869-894	Honeycomb
	UMTS frequency band VI	830-840	875-885
					GSM?900		890-915	935-960

The GSM network can be worked on any frequency band in the frequency band of table 1 li or other certain frequency band, and these frequency bands are collectively referred to as the GSM frequency band.Each GSM frequency band covers several 200KHz radio frequency (RF) channels.Each RF channel is identified by specific ARFCN (absolute RF channel number).For example, GSM 900 frequency bands cover ARFCN 1 to 124, and GSM 850 frequency bands cover ARFCN 128 to 251, and GSM 1800 frequency bands cover ARFCN 512 to 885, and GSM 1900 frequency bands cover ARFCN 512 to 810." the Digital cellular telecommunications system (Phase 2+) that is entitled as in available in September, 2000 of the public; Radio transmission and reception (digital cellular telecommunication systems (stage 2+); Transceiving) (distribution version 1999) " 3GPP TS 05.05 in provided the ARFCN of each GSM frequency band.The GSM network is typically worked on the specific one group of RF channel in specific GSM frequency band.The RF channel is also referred to as GSM channel and frequency channels.

The UMTS network can be worked on any frequency band in the frequency band of table 1 li or other certain frequency band, and these frequency bands are collectively referred to as the UMTS frequency band.Each UMTS frequency band can cover the UMTS channel of a plurality of about 5MHz in interval.Each UMTS channel has the bandwidth of 3.84MHz and with the given centre frequency of 200KHz resolution.Each UMTS channel number is identified by particular channel, and this channel number can be UARFC (UTRAARFCN).In the public 3GPP TS 25.101 that is entitled as " User Equipment (UE) radiotransmission and reception (FDD) (subscriber's installation (UE) transceiving (FDD)) (distribution version 7) " in available in March, 2006, provided the UARFCN of each UMTS frequency band.The UMTS network is typically worked on one or more specific UARFCN.The UMTS channel is also referred to as W-CDMA channel and frequency channels.

For honeycomb frequency, the UARFCN of UMTS is relevant with the ARFCN of GSM as follows:

UARFCN=5 * 824.2+0.2 * (ARFCN-128)+45} formula (1)

＝ARFCN+4218。

Cellular band covers ARFCN 128 to 251 and covers UARFCN 4357 to 4458 for UMTS for GSM on down link.

For PCS Personal Communications System (PCS) frequency band, the UARFCN of UMTS is relevant with the ARFCN of GSM as follows:

UARFCN=5 * 1850.2+0.2 * (ARFCN-512)+80} formula (2)

＝ARFCN-9139。

The PCS frequency band covers ARFCN 512 to 810 and covers UARFCN 9662 to 9938 for UMTS for GSM on down link.In allocated frequency band, UARFCN may lack than ARFCN, because may only define UARFCN for the part of this frequency band.For example, only for 871.4 to 891.6MHz in the cellular band and only defined UARFCN to 1987.6MHz for 1932.4 in the PCS frequency band.Formula (1) and (2) are the exemplary transformation formula to honeycomb and PCS frequency band.Also can be such as other frequency band such as GSM 900, GSM1800 and also define other conversion formula for other radiotechnicss such as for example cdma2000.

As shown in table 1, GSM and UMTS network can be worked on same frequency band or overlapping bands.For example, GSM 1900 frequency bands and UMTS frequency band II are corresponding to the PCS frequency band, and GSM 1800 frequency bands and UMTS frequency band III are corresponding to Digital Cellular System (DCS) frequency band.

Fig. 2 shows each layer of GSM and UMTS.GSM comprises non-access level (NAS) and inserts level (AS).NAS comprises support terminal and GSM network function and the agreement with traffic between the core net of its interface and signaling.AS comprises function of communicating by letter and the agreement between the interior MSC of support terminal and this GSM network.For GSM, AS comprises radio resource (RR) management sub-layer, radio link control (RLC) sublayer, medium access control (MAC) sublayer and physical layer.RR is the sublayer of layer 3.RLC and MAC are the sublayers that is also referred to as the layer 2 of data link layer.Physical layer is also referred to as layer 1.UMTS comprises NAS and AS similarly.For UMTS, AS is included in radio resource control (RRC) sublayer at layer 3 place, at the RLC at layer 2 place and media access control sublayer and in the physical layer at layer 1 place.

NAS, RRC and RR carry out various functions with search wireless network and foundation, maintenance and end call.In order to oversimplify, only describe and the search function associated following.Term " search " and " scanning " are used usually interchangeably.The RRC function can be realized by the RRC module in the terminal 150, and the RR function can be realized by the RR module.

Terminal 150 can be carried out manual search or search for automatically to seek PLMN.Terminal 150 can carried out manual search when the user asks.The purpose of manual search is to return the comprehensive list of all PLMN that found by terminal 150 to the user.If terminal 150 resides on the low PLMN of priority ratio Home PLMN temporarily, then it can periodically carry out automatic search.Automatically the purpose of search is to find the high PLMN of priority ratio current service PLMN.Terminal 150 can carried out search automatically when timer expires.Timer value can be determined by the service provider.For manually and automatically searching for both, terminal 150 all can carry out to the GSM network search (GSM search) and/or to the search (UMTS search) of UMTS network.Terminal 150 can be carried out manually and search automatically as described below in every way.

Fig. 3 shows the exemplary manual search procedure of being carried out by terminal 150 300.The manual search request receives (frame 312) by the radio resource entities of radiotechnics X from the user.The manual search request can send to terminal 150 current radio resource entities of staying or having received recently the radiotechnics of service temporarily.Radio resource entities can be the RR of GSM or the RRC of UMTS.Each radio resource entities can be carried out the search to PLMN on its oneself radiotechnics, carry out the search to PLMN on all the other the every kind radiotechnics of supporting in terminal 150.

On radiotechnics X, all frequency bands of enabling are carried out search (frame 314) to PLMN.The frequency band of enabling can be depending on the ability of terminal 150, the configuration and/or the other factors of terminal 150.Can carry out search to the band group that comprises honeycomb and PCS frequency band (it is commonly used in the U.S.), band group or other certain band group that comprises IMT-2000 and GSM 1800 frequency bands (it is commonly used in Europe).The tabulation of the PLMN that finds at radiotechnics X is saved (frame 316).Make definite (frame 318) that whether have another radiotechnics to search for subsequently.If answer is a "Yes", then on this another radiotechnics, all of this another radiotechnics is enabled frequency band and carry out search (frame 320) PLMN.The tabulation of the PLMN that finds at this another radiotechnics is provided for the radio resource entities (frame 322) of radiotechnics X.This process turns back to frame 318 subsequently.If the answer to frame 318 is a "No", then is generated as the tabulation of all PLMN that all radiotechnicss find and it is returned to user's (frame 324).

In manual search process 300, carry out search independently at every kind of radiotechnics that terminal 150 is supported.For example, terminal 150 receives at the RR by GSM and can carry out the GSM search under the situation of manual search request and search for succeeded by UMTS.For example, terminal 150 receives at the RRC by UMTS and can carry out the UMTS search under the situation of manual search request and search for succeeded by GSM.

Terminal 150 can be carried out the GSM search to allocated frequency band (for example, cellular band), and is as follows:

Carry out power scan and measure the power of receiving of each GSM channel in this frequency band,

Identify strong GSM channel,

On each strong GSM channel, attempt catching, and

The tabulation of the GSM channel that report is caught with PLMN information.

Power scan provides to be measured the signal strength indicator (RSSI) of receiving of each GSM channel in the frequency band.Power scan can be carried out relatively apace, for example in some seconds.Select strong GSM channel (for example, having those of the rssi measurement that is higher than threshold value) to catch, and abandon all the other weak GSM channels.May need (1) to detect to the seizure of strong GSM channel and go up that the frequency that sends is transferred and (2) decoding is gone up the paroxysm that sends to obtain the basic transceiver station identity code (BSIC) of GSM cellular cell in synchronizing channel (SCH) at frequency correction channel (FCCH).Seizure to strong GSM channel may also need to decode Broadcast Control Channel (BCCH) to obtain system information type 3 message (SI3) or system information type 4 message (SI4).SI3 and SI4 comprise about the information of the PLMN of GSM cellular cell and out of Memory.Generally speaking, successfully catch can detect by the FCCH of success, successful FCCH detects and SCH decode, successful FCCH detection and SCH and BCCH decode both or defined by some other criterion.In any case, the GSM search provides the tabulation of catching the GSM channel.This tabulation can comprise zero, one or more GSM channel.

Terminal 150 can be carried out the UMTS search to allocated frequency band, and is as follows:

Carry out coarse frequency scanning and measure interval delta f _CCoarse frequency on receive power,

Identify strong coarse frequency,

UARFCN to scope around each strong coarse frequency carries out thin frequency scanning,

Identify strong UARFCN,

On each strong UARFCN, attempt catching, and

The tabulation of the UMTS channel that report is caught with PLMN information.

Fig. 4 shows at the exemplary coarse frequency scanning of UMTS and thin frequency scanning.Coarse frequency scanning can be in interested whole frequency band---for example PCS frequency band---goes up and carries out.Coarse frequency scanning provides interval delta f _CThe rssi measurement of coarse frequency.For example, Δ f _CCan equal 2MHz, and scanning can provide at f to the coarse frequency of PCS frequency band _k=1930+2k MHz---k=0 wherein ..., 30---31 rssi measurements of 31 coarse frequencies locating.Can be with these rssi measurements comparison detection threshold, and the strong coarse frequency that can select to have the rssi measurement that is higher than detection threshold is further to estimate.

To each strong coarse frequency f _kCan be at f _FL=f _k-Δ f _C/ 2 to f _FU=f _k+ Δ f _CCarry out thin frequency scanning on/2 the frequency range.Thin frequency scanning provides dropping on the rssi measurement of all UARFCN in this frequency range.For example, f _CCan equal 2MHz, and to coarse frequency f _kThin frequency scanning 11 rssi measurements separating the UARFCN of 200KHz to 11 can be provided.Can be with these to the rssi measurement of UARFCN comparison detection threshold, and the strong UARFCN that can select to have the rssi measurement that is higher than detection threshold is to catch.

The process that terminal 150 can use branch three to go on foot is attempted the seizure on each strong UARFCN.In step 1, terminal 150 is by making the relevant PSC sequence that goes up 256 chips that send at primary synchronization channel (SCH) of searching for the local Primary Synchronisation Code in different time skew place (PSC) sequence that generates of the sample that receives at terminal 150 places.Terminal 150 uses PSC to detect the existence of UMTS cellular cell and base when finding out the crack of this cellular cell.In step 2, terminal 150 is determined the sign indicating number type of secondary synchronous code (SSC) sequence of each UMTS cellular cell use that its PSC has been detected.Terminal 150 can be based on the frame time base and the scrambling code group that the detected SSC sign indicating number of UMTS cellular cell type are identified for this cellular cell.In step 3, terminal 150 is determined the employed scrambled code of each UMTS cellular cell that its SSC sign indicating number type has been detected.Eight scrambled codes of each SSC sign indicating number type and a group are associated.Which scrambled code is in terminal 150 these eight scrambled codes of evaluation each be with what determine the use of UMTS cellular cell.

As shown in Figure 4, having many UARFCN will attempt catching.As example, the PCS frequency band covers the UARFCN more than 200, and can attempt catching on 200 or the more UARFCN in the PCS frequency band.Therefore, the UMTS search may need long-time (for example, some minutes) to finish.

In one embodiment, the result of GSM search is used to reduce the frequency search space that UMTS searches for.The GSM search provides the tabulation of the GSM channel of catching.For fear of the interference between GSM and the UMTS, GSM channel and UMTS channel typically are selected to they are not overlapped each other on frequency.Therefore, for each GSM channel of catching, can make the supposition that does not have overlapping this GSM channel of UMTS.It is the frequency of the scope at center that the UMTS search can be saved the GSM channel of catching with each subsequently.

The result that Fig. 5 shows based on the GSM search saves frequency from the UMTS frequency search space.In this example, catch five GSM channels at the GSM searching period.Each GSM channel has the three dB bandwidth less than 200KHz, and each UMTS channel has the three dB bandwidth of about 3.84MHz.For each GSM channel of catching, can save the frequency range that on each side of this GSM channel cover-most reaches 3.84MHz from UMTS search.Alternatively, can save less frequency range so that some limits to be provided.In one embodiment, for each GSM channel of catching, from the UMTS frequency search space frequency range that to save with this GSM channel be the 6.8MHz at center.Other frequency range except that 6.8MHz also can be used.

The frequency space of saving is to be made of the union that is all frequency ranges of saving at center with all GSM channels of being caught.The frequency space of being saved comprises and can search for all frequencies of saving from UMTS.Frequency search space to the UMTS of allocated frequency band search can comprise that subsequently all are not included in the frequency in the frequency space of being saved.The number and the frequency thereof that depend on the GSM channel of catching can be saved most of frequency band from frequency search space.Although can---is on less frequency---carry out the UMTS search for coarse frequency and thin frequency scanning in the above described manner on the frequency search space then.

Fig. 6 illustrates use and reduces embodiment at the manual search process 600 of the frequency search space of UMTS at the Search Results of GSM.The manual search request is by the radio resource entities of radiotechnics X---for example the RRC of the RR of GSM or UMTS---receives (frame 612) from the user.To the search (frame 614) of all frequency bands of enabling execution to GSM PLMN.The tabulation of the PLMN that finds for GSM is saved (frame 616).As mentioned above, determine (frame 618) at the frequency search space of UMTS based on the GSM channel of being caught.On this frequency search space, carry out search (frame 620) subsequently to UMTS PLMN.The tabulation of the PLMN that finds for UMTS is saved (frame 622).Be generated as the tabulation of all PLMN that GSM and UMTS find and it is returned to user's (frame 624).

Terminal 150 can bimodulus, only GSM pattern or only UMTS pattern work.Terminal 150 can receive service from GSM or UMTS under bimodulus.Mode of operation can be selected or disposed by the service provider by the user, for example, disposes based on the position of terminal 150.If terminal 150 is operated in only under the UMTS pattern, then it can save the search to GSM PLMN in frame 614.

In one embodiment, terminal 150 is safeguarded acquisition database, and this database comprises the tabulation of the uniqueness UARFCN/PLMN clauses and subclauses of previous UMTS channel of having been caught by terminal 150.The indication of each UARFCN/PLMN clauses and subclauses is used to catch the UARFCN, scrambled code of the UMTS channel that is associated and other for information about.Acquisition database can comprise predetermined number (for example, 10) clauses and subclauses recently, and these clauses and subclauses can be stored in the circular buffer so that the oldest clauses and subclauses in the new clauses and subclauses replacement data storehouse.

Terminal 150 can attempt catching on the UMTS channel in acquisition database before carrying out the UMTS search.This may be former thereby desirable because of some.At first, terminal 150 had before been caught these UMTS channels, and the likelihood of therefore catching these UMTS channels once more can be preferable.The second, terminal 150 has such as relevant informations such as scrambled codes and perhaps can catch these UMTS channels fast.

In one embodiment, the result of acquisition database search is used to reduce the frequency search space that UMTS searches for.Terminal 150 can attempt catching on each the UMTS channel in acquisition database, and catches the UMTS channel and may success also may get nowhere.If the UMTS channel is not hunted down, then can from the UMTS search, save the UARFCN of this UMTS channel.If the UMTS channel is hunted down, then can be from the UMTS search frequency that to save with this UMTS channel of being caught be the scope at center.

Fig. 7 shows based on the result who catches data search and saves frequency from the UMTS frequency search space.In this example, by the acquisition database search, there are two UMTS channels to be hunted down, and have three UMTS channels not caught by it.For each UMTS channel of catching, can save the frequency range that cover-most on each side of UARFCN of this UMTS channel reaches 3.84MHz from the UMTS frequency search space.In one embodiment, for each UMTS channel of catching, the UARFCN that saves with this UMTS channel from the UMTS frequency search space is the frequency range of the 6.8MHz at center.Other frequency range also can be used.

Fig. 8 illustrates the embodiment of search procedure 800 that the result who uses the acquisition database search reduces the frequency search space of UMTS search.The initial acquisition database of carrying out is searched for (frame 810).For frame 810, attempt on the UMTS channel in acquisition database catching (frame 812).If catch successfully, as determining in frame 814, then the UARFCN that saves with the UMTS channel of being caught from the UMTS frequency search space is the frequency range (frame 816) at center.Get nowhere if catch, then save the UARFCN (frame 818) of the UMTS channel of not catching from the UMTS frequency search space.Be made in definite (frame 820) that whether another UMTS channel that will attempt catching is arranged in the acquisition database subsequently.If answer is a "Yes", then this process turns back to frame 812 to attempt seizure on another UMTS channel in acquisition database.Otherwise, if on all the UMTS channels in the acquisition database, attempted seizure, then in the search of in frame 816 and/or 818, carrying out on the frequency search space of reduction UMTS PLMN (frame 822).

Terminal 150 can periodically be carried out automatic search to seek the high PLMN of priority ratio current service PLMN.Because the purpose of search is to find the PLMN of higher priority automatically, so terminal 150 can be searched for PLMN based on the priority of PLMN.If because of GSM is that higher priority is at first carried out the GSM search, then the result of GSM search can be used for reducing the frequency search space that UMTS searches for.

Fig. 9 shows the embodiment of automatic search procedure 900.The indication of carrying out search automatically receives (frame 912) by radio resource entities.This indication can be triggered by the expiring of timer that is used for search automatically.This indication can (for example, NAS) be sent, and can comprise the search listing of the PLMN that the current PLMN of priority ratio is high by the upper strata.This search listing can be derived from the preferred PLMN tabulation of terminal 150 preparations.Limit priority PLMN in this search listing is identified out (frame 914).Whether make this limit priority PLMN subsequently is determine (frame 916) of GSM PLMN.

If limit priority PLMN is GSM PLMN, then the search of GSM PLMN is enabled frequency band to all and carry out (frame 920).Inspection by all GSM channels of GSM code acquisition to determine whether have any channel to belong to limit priority GSM PLMN in these GSM channels.Make determine (frame 922) that whether finds limit priority GSM PLMN subsequently.If answer is a "Yes", then GSM searches for the PLMN that finds and be included in the search listing and is returned (frame 952) thus, and this process stops.Otherwise,, then attempt on the UMTS channel in acquisition database catching (frame 924) if do not find limit priority GSM PLMN.For the acquisition database in the frame 924 search, can use the result of GSM search to save and UMTS channel by the GSM channel overlap of GSM code acquisition.Make determine (frame 926) that whether finds limit priority UMTS PLMN subsequently.If answer is a "Yes", then UMTS searches for the PLMN that finds and be included in the search listing and is returned (frame 952) thus, and this process stops.Otherwise if do not find limit priority UMTS PLMN, then the result based on acquisition database search in the result of GSM search in the frame 920 and the frame 924 determines the frequency search space (frame 928) that UMTS searches for.On this UMTS frequency search space, carry out search (frame 930) subsequently to UMTS PLMN.The PLMN that any search of UMTS is thus found and is included in the search listing is returned (frame 952), and this process stops.

If the limit priority PLMN in the search listing is UMTS PLMN,, then attempt on the UMTS channel in acquisition database catching (frame 940) as in frame 916, determining.Make determine (frame 942) that whether finds limit priority UMTS PLMN subsequently.If answer is a "Yes", then the acquisition database search PLMN that finds and be included in the search listing is returned (frame 952) thus, and this process stops.Otherwise,, then determine the frequency search space (frame 944) of UMTS search based on the result of acquisition database search if do not find limit priority UMTS PLMN.On this UMTS frequency search space, carry out search (frame 946) subsequently to UMTS PLMN.Make determine (frame 948) that whether finds limit priority UMTS PLMN subsequently.If answer is a "Yes", then UMTS searches for the PLMN that finds and be included in the search listing and is returned (frame 952) thus, and this process stops.Otherwise, if do not find limit priority UMTS PLMN, then to all being enabled the search (frame 950) of frequency band execution to GSMPLMN.For the GSM in the frame 950 search, can use the result of the result of acquisition database search and UMTS search save with search formerly in the GSM channel of the UMTS channel overlap of catching.GSM searches for the PLMN that finds and be included in the search listing and is returned (frame 952) thus, and this process stops.

In the embodiment shown in Fig. 9, stop during the limit priority PLMN of process 900 in finding search listing or after having searched for GSM and UMTS.Process 900 also can stop when finding higher priority PLMN and/or satisfy other certain criterion.

In the embodiment shown in Fig. 9, depend on the output of expectation, GSM search, UMTS search and acquisition database search can be carried out by different order.Generally speaking, can use the result of given search to reduce the frequency search space of subsequent searches.

Figure 10 shows the embodiment that is used for obtaining from wireless network the process 1000 of service.At first, receive service request, for example receive (frame 1012) in energising or when losing service.As early as possible from any network---no matter be that UMTS or GSM acquisition service may be desirable.Attempt on the PLMN in acquisition database catching (frame 1014).If find any PLMN in the acquisition database,, then obtain service (frame 1018) from this PLMN as determined in frame 1016.

Otherwise, if do not find PLMN in the acquisition database, then can carry out the GSM search, lack and on GSM PLMN, can obtain service quickly because the GSM search may be searched for the time spent amount than UMTS.Determine the frequency search space (frame 1022) of GSM search based on the result of acquisition database search.For example, can save the UARFCN of each UMTS channel of frame 1014, not catching from the GSM frequency search space.On this GSM frequency search space, carry out search (frame 1024) subsequently to GSM PLMN.If find any GSM PLMN,, then obtain service (frame 1028) from this PLMN as determined in frame 1026.

Otherwise if do not find GSM PLMN, then the result based on GSM search in the result of acquisition database search in the frame 1014 and the frame 1024 determines the frequency search space (frame 1032) that UMTS searches for.For example, can save the UARFCN of each UMTS channel of frame 1014, not catching and corresponding to the UARFCN of the scope of each GSM channel of in frame 1024, catching from the UMTS frequency search space.On this UMTS frequency search space, carry out search (frame 1034) subsequently to UMTS PLMN.If find any UMTS PLMN,, then obtain service (frame 1038) from this PLMN as determined in frame 1036.Otherwise,, then return the response (frame 1040) of not finding service if do not find UMTS PLMN.

In another embodiment, if in frame 1026, do not find GSM PLMN, then attempt catching on the PLMN in acquisition database before the search of the UMTS in carrying out frame 1034.In another embodiment, if for example UMTS is preferable over GSM, then before the GSM search, carry out the UMTS search earlier.Also can carry out search by other order.

Fig. 6,8,9 and 10 illustrates the examplar search process at GSM and UMTS.Generally speaking, can carry out by any order at the search of GSM and UMTS.These search also can be carried out in response to any trigger event or criterion.For example, process 1000 also can be used for manual search or search automatically.

Figure 11 shows the embodiment at the search procedure 1100 of multiple radiotechnics.Execution is at first search of first radiotechnics, and obtains to be designated as the Search Results (frame 1112) of the frequency channels that this first radiotechnics catches.Use this first Search Results of searching for to carry out and save frequency (frame 1114) to search for from second at second search of second radiotechnics.First radiotechnics may have than second radiotechnics search time faster.First and second radiotechnicss can be respectively GSM and W-CDMA, or some other radiotechnics.

First search can comprise and obtains receiving power measurement, having the tabulation of attempting catching and be provided as the frequency channels that first radiotechnics successfully catches on the frequency channels of receiving power measurement by force of a plurality of frequency channels.First radiotechnics can be GSM, can catch by detecting FCCH, decoding SCH and the BCCH that may decode in addition and have each frequency channels of receiving power measurement by force.

Can be that second radiotechnics is determined frequency search space based on the result of first search.Can save be first radiotechnics each frequency channels of successfully catching around the frequency of scope.Can on this frequency search space, carry out second search subsequently.

Second search can comprise a plurality of frequencies of getting rid of the frequency of saving from second search receive power measurement, be the tabulation that the frequency channels at center attempts catching and be provided as the frequency channels that second radiotechnics successfully catches to have the frequency of receiving power measurement by force.Receive that power measurement can be via following acquisition: (1) carries out coarse frequency scanning to a plurality of coarse frequencies of getting rid of the frequency of saving from second search; And (2) carry out thin frequency scanning to a plurality of thin frequency that each has the coarse frequency of receiving power measurement by force.Thin frequency can be corresponding to the UARFCN among the UMTS.

First and second search can be in response to the indication of request, the search priority of the tabulation of all available wireless network wireless network higher than current wireless network, carry out the request of service etc.

Figure 12 shows the embodiment at the search procedure 1200 of radiotechnics.Formerly be to carry out on first radiotechnics at least one frequency channels of catching to catch (frame 1212).Use the result of this seizure to carry out subsequently and save frequency (frame 1214) with search at the search of first radiotechnics.For frame 1214, the frequency of being saved can comprise: the frequency of the centre frequency of each frequency channels that does not successfully catch (1) and the scope of each frequency channels that successfully catch (2).

Search can be carried out, and the result of the frequency channels that this second radiotechnics catches can be obtained to be designated as at second radiotechnics.Can use this result who catches subsequently and carry out at the search of first radiotechnics with from saving frequency at the search of first radiotechnics at the result of the search of second radiotechnics.Alternatively, can at first carry out search, and can use the result of this search to come from saving frequency at the search of second radiotechnics at first radiotechnics.First and second radiotechnicss can be respectively W-CDMA and GSM, or some other radiotechnics.

Generally speaking, terminal 150 can use result at a kind of search of radiotechnics to come to be another search reduction search volume at same wireless power technology or different radio power technology.First search can be full search (for example, the search on whole frequency band) or part search (for example, the seizure on the frequency channels in acquisition database).Second search also can be full search or part search.The frequency that will save from the search volume can be depending on the bandwidth and/or the other factors of the frequency channels that is first code acquisition or the frequency channels of not catching, first and second radiotechnicss.

In one embodiment, terminal 150 attempts reducing the search volume of this frequency band based on the result to the prior searches of each frequency band that will search for.In another embodiment, terminal 150 is only attempted the reduction search volume at the crowded frequency band that is used for multiple radiotechnics.For example, cellular band, PCS frequency band, GSM 900 frequency bands and GSM1800 frequency band can be regarded as crowded frequency band, because UMTS and GSM network both are deployed on these frequency bands.The IMT-2000 frequency band is not crowded frequency band at present, because current only UMTS network is deployed on this frequency band.In the future, along with increasing wireless network is disposed, it is crowded that other frequency band may become.

Search skill and technique as herein described can provide and go up sizable reduction search time.In a kind of exemplary design, the search volume of using the GSM Search Results to reduce the UMTS search provides last 10 to 30 seconds saving UMTS search time.For other design, the improvement amount may be different.

Figure 13 shows the block diagram of the embodiment of terminal 150.On down link, antenna 1312 is from GSM and/or the UMTS base station receives modulated signal and provide to receiver (RCVR) 1314 and to receive signal.Signal is received in receiver 1314 conditionings (for example, filtering, amplification and down-conversion), the signal of digitlization through nursing one's health, and data sample is provided.Demodulator (DEMOD) 1316 is handled (for example, descrambling, separate channelizing and demodulation) data sample and symbol estimation is provided, and symbol estimation is to be the estimation of the data symbols that sends of terminal 150 to the base station.Decoder 1318 with reprocessing (for example, deinterleaving and decoding) symbol estimation and for terminal 150 provide through the decoding data.For different radiotechnicss, the processing typical case who is undertaken by demodulator 1316 and decoder 1318 is different.For example, for GSM, demodulator 1316 can be carried out matched filtering and equilibrium.For W-CDMA, demodulator 1316 can be carried out descrambling, carry out despreading, carries out data demodulates etc. with orthogonal variable spreading factor (OVSF) sign indicating number with scramble sequence.

On up link, according to the radiotechnics that is suitable for, for example GSM or W-CDMA, to (for example handle by encoder 1332 by traffic data and signaling that terminal 150 sends, coding and interweave), and further handle (for example, modulation, channelizing and scrambling) by modulator (MOD) 1334.Transmitter (TMTR) 1336 conditionings (for example, converting simulation, amplification, filtering and up-conversion to) will be via the uplink signal of antenna 1312 to the transmission of one or more base stations from the data chips and the generation of modulator 1334.

The operation at controller/processor 1320 control terminals 150 places.But controller/processor 1320 implementation procedure 300,600,800,900,1000,1100,1200 and/or other processes.Controller/processor 1320 also can be realized NAS, RRC and/or RR.Controller/processor 1320 can determine when to the service execution manual search, search for automatically and systematic search, and also can determine to search for which PLMN and which frequency channels and/or frequency band.Controller/processor 1320 also can instruct acquisition database search, GSM search and UMTS search.Demodulator 1316 can be UMTS and GSM realizes layer 1, carries out acquisition database search and UMTS search when being instructed by RRC, and UMTS result is provided, and carries out the GSM search when being instructed by RR, and GSM is provided Search Results.The data and the program code of memory 1322 storage terminals 150.Memory 1322 can be stored PLMN information, acquisition database, Search Results etc.

For the purpose of distinct, specifically the search skill and technique has been described at UMTS and GSM.These skill and technique also can be used for other network, such as cdma2000 network, wireless lan (wlan) etc.These skill and technique also can be used for two or more radiotechnicss, for example are used for W-CDMA, GSM and cdma2000.

Search skill and technique as herein described can realize by various means.For example, these skill and technique can realize in hardware, firmware, software or its combination.Realize that for hardware the processing unit that is used to carry out search can be at one or more application-specific integrated circuit (ASIC)s (ASIC), digital signal processor (DSP), digital signal processor spare (DSPD), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, be designed to carry out realization in other electronic unit of function described herein or its combination.

Realize that for firmware and/or software these skill and technique can realize with the module (for example, process, function etc.) of carrying out function described herein.Firmware and/or software code can be stored in the memory (for example, the memory among Figure 13 1322) and by processor (for example, processor 1320) and carry out.Memory can be realized in processor, or be implemented in the memory outside.

It is in order to make any technical staff in this area all can make or use the present invention that above description to the disclosed embodiments is provided.Various modifications to these embodiment are obvious by those skilled in the art easily, and can be applied to other embodiment and can not break away from the spirit or scope of the present invention in this defined generic principles.Thereby the present invention is intended to be defined to shown embodiment herein, but should be awarded the scope with principle disclosed herein and the corresponding to broad sense of novel features.

Claims (37)

1. device comprises:

At least one processor, it is configured to carry out at first search of first radiotechnics and obtains to be designated as the Search Results of the frequency channels that described first radiotechnics catches, and uses the described Search Results of described first search to carry out second search at second radiotechnics to save frequency from described second search; And

Be coupled to the memory of described at least one processor.

2. device as claimed in claim 1 is characterized in that, described first radiotechnics is GSM, and described second radiotechnics is W-CDMA.

3. device as claimed in claim 1, it is characterized in that, for described first search, described at least one processor is configured to obtain receiving power measurement, have the tabulation of attempting catching and be provided as the frequency channels that described first radiotechnics successfully catches on the frequency channels of receiving power measurement by force a plurality of frequency channels.

4. device as claimed in claim 3, it is characterized in that, described first radiotechnics is GSM, and wherein have the frequency channels of receiving power measurement by force for each, described at least one processor is configured to detect frequency correction channel (FCCH) and the synchronizing channel of decoding (SCH) is caught described frequency channels.

5. device as claimed in claim 4 is characterized in that, has the frequency channels of receiving power measurement by force for each, and described at least one processor Broadcast Control Channel (BCCH) that also is configured to decode is caught described frequency channels.

6. device as claimed in claim 1 is characterized in that, described at least one processor is configured to save the frequency of scope around each frequency channels of successfully catching for described first radiotechnics.

7. device as claimed in claim 1, it is characterized in that, described at least one processor is configured to determine frequency search space at described second radiotechnics based on the described Search Results of described first search, and carries out described second and search on described frequency search space.

8. device as claimed in claim 1, it is characterized in that, for described second search, described at least one processor be configured to obtain to a plurality of frequencies of having got rid of the described frequency of saving from described second search receive power measurement, be the tabulation that the frequency channels at center attempts catching and be provided as the frequency channels that described second radiotechnics successfully catches to have the frequency of receiving power measurement by force.

9. device as claimed in claim 1, it is characterized in that, for described second search, described at least one processor is configured to carry out coarse frequency scanning and obtains receiving power measurement, a plurality of thin frequency with each coarse frequency of receiving power measurement is by force carried out thin frequency scanning and obtained to receive power measurement and be that the frequency channels at center is attempted catching to have the thin frequency of receiving power measurement by force a plurality of coarse frequencies of having got rid of the described frequency of saving from described second search.

10. device as claimed in claim 1 is characterized in that, described at least one processor is configured to receive to the request of the tabulation of all available wireless network and in response to described request carries out described first and second search.

11. device as claimed in claim 1 is characterized in that, described at least one processor is configured to receive the indication of search priority at least one wireless network higher than current wireless network and carries out described first and second search in response to described indication.

12. device as claimed in claim 1, it is characterized in that it is that both all are deployed under the situation that frequency band wherein carries out and save described frequency from described second search to described first and second radiotechnicss that described at least one processor is configured in described first and second search.

13. device as claimed in claim 1, it is characterized in that it is to save described frequency from described second search under the situation that cellular band, PCS frequency band, GSM900 frequency band or GSM1800 frequency band are carried out that described at least one processor is configured in described first and second search.

14. a method comprises:

Execution is at first search of first radiotechnics and obtain to be designated as the Search Results of the frequency channels that described first radiotechnics catches; And

Use the described first described Search Results of searching for to carry out and save frequency to search for from described second at second search of second radiotechnics.

15. method as claimed in claim 14 is characterized in that, described execution comprises at first search of first radiotechnics

Acquisition is to the power measurement of receiving of a plurality of frequency channels,

Have trial seizure on the frequency channels of receiving power measurement by force, and

Be provided as the tabulation of the frequency channels that described first radiotechnics successfully catches.

16. method as claimed in claim 14 is characterized in that, also comprises:

Save the frequency of scope around each frequency channels of successfully catching for described first radiotechnics.

17. method as claimed in claim 14 is characterized in that, described execution comprises at second search of second radiotechnics

Acquisition has been to having got rid of the power measurement of receiving from a plurality of frequencies of the described second described frequency saved of search,

Attempting on the frequency channels that the frequency of receiving power measurement by force is the center catching to have, and

Be provided as the tabulation of the frequency channels that described second radiotechnics successfully catches.

18. a device comprises:

Be used to carry out at first search of first radiotechnics and obtain to be designated as the device of the Search Results of the frequency channels that described first radiotechnics catches; And

Being used to use the described first described Search Results of searching for to carry out at second of second radiotechnics searches for to save the device of frequency from described second search.

19. device as claimed in claim 18 is characterized in that, also comprises:

Be used to save the device of the frequency of scope around each frequency channels of successfully catching for described first radiotechnics.

20. one kind is used to store the processor readable medium that can operate following instruction:

Guidance is at first search of first radiotechnics and obtain to be designated as the Search Results of the frequency channels that described first radiotechnics catches; And

Use the described first described Search Results of searching for to instruct and save frequency to search for from described second at second search of second radiotechnics.

21. processor readable medium as claimed in claim 20 is characterized in that, also is used to store to operate following instruction:

Save the frequency of scope around each frequency channels of successfully catching for described first radiotechnics.

22. a device comprises:

At least one processor, it is configured to formerly is to carry out on first radiotechnics at least one frequency channels of catching to catch, and uses the result of described seizure to carry out search at described first radiotechnics to save frequency from described search; And

Be coupled to the memory of described at least one processor.

23. device as claimed in claim 22 is characterized in that, described at least one processor is configured to save the centre frequency of each frequency channels of successfully catching and saves the frequency of the scope of each frequency channels that success catches.

24. device as claimed in claim 22, it is characterized in that, described at least one processor is configured to carry out the result who is designated as the frequency channels that described second radiotechnics catches at the search of second radiotechnics and acquisition, and uses the described result of described described result who catches and described search at second radiotechnics to carry out described search at first radiotechnics to save frequency from described search at first radiotechnics.

25. device as claimed in claim 24 is characterized in that, described at least one processor is configured to save the frequency of scope around each frequency channels of successfully catching for described second radiotechnics.

26. device as claimed in claim 24 is characterized in that, described first radiotechnics is W-CDMA, and described second radiotechnics is GSM.

27. device as claimed in claim 22 is characterized in that, described at least one processor is configured to receive the request of the service of searching and carries out described seizure and described search in response to described request.

28. device as claimed in claim 22 is characterized in that, described at least one processor is configured to receive the indication of search priority at least one wireless network higher than current wireless network and carries out described seizure and described search in response to described indication.

29. a method comprises:

Formerly be to carry out on first radiotechnics at least one frequency channels of catching to catch; And

Use the result of described seizure to carry out search at described first radiotechnics to save frequency from described search.

30. method as claimed in claim 29 is characterized in that, also comprises:

Save the centre frequency of each frequency channels of successfully not catching; And

Save the frequency of the scope of each frequency channels that success catches.

31. method as claimed in claim 29 is characterized in that, also comprises:

Execution is designated as the result of the frequency channels that described second radiotechnics catches at the search of second radiotechnics and acquisition, and

Wherein said search at first radiotechnics be to use that the described result of described result who catches and described search at second radiotechnics carries out to save frequency from described search at first radiotechnics.

32. a device comprises:

Be used for formerly is to carry out the device of catching on first radiotechnics at least one frequency channels of catching; And

Be used to use the result of described seizure to carry out search at described first radiotechnics to save the device of frequency from described search.

33. device as claimed in claim 32 is characterized in that, also comprises:

Be used to save device the centre frequency of each frequency channels of successfully not catching; And

Be used to save the device of frequency of the scope of each frequency channels that success catches.

34. device as claimed in claim 32 is characterized in that, also comprises:

Be used to carry out the device that is designated as the result of the frequency channels that described second radiotechnics catches at the search of second radiotechnics and acquisition, and wherein said search at first radiotechnics be to use that the described result of described result who catches and described search at second radiotechnics carries out to save frequency from described search at first radiotechnics.

35. one kind is used to store the processor readable medium that can operate following instruction:

Formerly be to instruct on first radiotechnics at least one frequency channels of catching to catch; And

Use the result of described seizure to instruct search at described first radiotechnics to save frequency from described search.

36. processor readable medium as claimed in claim 35 is characterized in that, also is used to store to operate following instruction:

Save the centre frequency of each frequency channels of successfully not catching; And

Save the frequency of the scope of each frequency channels that success catches.

37. processor readable medium as claimed in claim 35 is characterized in that, also is used to store to operate following instruction:

Guidance is designated as the result of the frequency channels that described second radiotechnics catches at the search of second radiotechnics and acquisition; And

Use the described result of described result who catches and described search at second radiotechnics to instruct described search at first radiotechnics to save frequency from described search at first radiotechnics.

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