CN102958123B

CN102958123B - Mobile terminal is switched to the method for Target cell, wireless communication system and equipment

Info

Publication number: CN102958123B
Application number: CN201110252823.XA
Authority: CN
Inventors: 焦文华
Original assignee: Alcatel Lucent SAS
Current assignee: Alcatel Lucent SAS
Priority date: 2011-08-30
Filing date: 2011-08-30
Publication date: 2016-03-02
Anticipated expiration: 2031-08-30
Also published as: CN102958123A

Abstract

The present invention relates to a kind of method and apparatus for mobile terminal being switched to Target cell.The method comprises: determine the positional information of mobile terminal in base station for each target candidate community in Active Set; And based on the positional information of described mobile terminal with reference to the pilot frequency intensity decision-making of the target candidate community in described Active Set to the switching of described target candidate community.By implementing embodiments of the invention, the frequent switching problem that may occur can be suppressed, and make full use of the high speed data transfer of little community, the call drop that switches more and cause can also be reduced over to improve Consumer's Experience, even can also carry out load balance based on the positional information of such as speed, such as high speed mobile terminal will have more multimachine and can be served by macrocell, and low speed mobile terminal will more may be served by Microcell.

Description

Mobile terminal is switched to the method for Target cell, wireless communication system and equipment

Technical field

The present invention relates to radio communication, more specifically, relate in a wireless communication system mobile terminal to the switching of Target cell.

Background technology

Along with widely using of smart phone, data service presents tidal effect along with the change of Time and place.And network technology has developed into forth generation digital communication (being called for short 4G) technology from third generation digital communication (be called for short 3G) technology, meet people to sooner, the demand of transmitted data amount and multiple business more.CDMAEVDO technology is one of 3G (Third Generation) Moblie (being called for short 3G) technology, and it has higher data throughout, and can provide data, services at a high speed, be the good technology for data, services.In 3GPP2 standard, EVDO is also referred to as HRPD.And LTE technology is 4G mobile communication mainstream technology, the peak rate of descending 326Mbit/s and up 86Mbit/s can be provided under 20MHz spectral bandwidth, improve the performance of Cell Edge User, improve cell capacity and reduce system delay.

In downtown, airport, the hot zones such as railway station or bus stop the high density of mobile device use, make to be covered by focus to improve communication quality and necessitate.Along with people are to the further increase of capacity requirement, in current cellular mobile telecommunication system, mainly through introducing microcellulor and Pico cell (in an embodiment of the present invention under macrocellular, the two can be integrated general reference for Microcell, English and Picocell, corresponding with macrocell) to provide more " including " honeycomb, form hierarchical cellular structure, thus " blind spot " and " focus " in solution network, improve network capacity.Microcell radius is much smaller compared with macrocell, can provide very high volume of business.The general covering radius in Microcell is approximately 0.1km ~ 1km.The typical radius of society of Pico cell, between 0.01 ~ 0.1km, is less than 50m usually.

Micro-cell solution can the cost extended wireless network coverage and capacity effectively, and simultaneously from the grand network offload voice-and-data traffic carrying capacity of mobile operator.By being deployed in neatly in family, enterprise and hot spot region, city, and provide service-specific to resident, enterprise and city focus, data service throughput and voice capacity can be improved in Microcell.Along with the development of LTE technology, LTE technology can be adopted to be used as focus and to cover.Since in most of the cases, the frequency that LTE (its operating frequency is generally 2.4G or 5.8G) works than EVDO (operating frequency is generally 800M etc.) is higher, and its overlay area is less, therefore LTE community also can regard the Microcell of a type as.Meanwhile, it is also attractive for using the Microcell of EVDO technology to cover for the focus not wanting to dispose very soon LTE carrier wave due to policy and technical risk.

Some researchs concentrate on disposes little community at cell edge and center.Research display, compared with arranging with center of housing estate Microcell, cell edge is disposed can provide better performance.

Such as, Fig. 1 shows the many picocell deployment in typical macrocell, wherein there is a sector, 19 community/57, in this deployment, (covering radius is in 100 meters Microcell, 4, each sector, illustrate with triangle) dispose at cell edge, grand in macro station point distance 1732 meters, slightly to macro station point distance 700 meters.

To those skilled in the art, macrocell can use EVDO technology, and Microcell also can use EVDO or LTE technology.

Fig. 2 illustrates that typical Microcell and macrocell mix deployment situation, and wherein macrocell and Microcell manage by operator.As shown in Figure 2, Microcell is deployed in macrocell edge usually.If mobile terminal (MS) enters overlay area, Microcell, then it can detect the pilot tone from adjacent macro cell simultaneously.

Fig. 3 is exemplified with the schematic diagram switched in situation shown in fig. 2.In order to clearly demonstrate Problems existing, assuming that the radius of Microcell is 50 meters.If mobile terminal is mobile to C (A, B and C arrange in the drawings from right to left) through B from A with 50 kilometers/hour, mobile terminal will stop at most 7 (i.e. 2*50/ (50/3.6)=7) second in this Microcell.As a rule, in fact it only stops within 5 seconds in Microcell.If Microcell and macrocell are all based on EVDO, then switching time will be 300ms.If Microcell is based on LTE, macrocell is based on EVDO, and situation is by even worse.About 6-8 second will be spent the unoptimizable switching time between EVDO and LTE.

And the covering of Microcell is limited to very much, this means this mobile terminal complete be switched to Microcell before will leave this LTE Microcell cover.Therefore, if mobile terminal moves to B, point enters into Microcell, mobile terminal is just started to switch to Microcell, then probably before switching completes, mobile terminal has moved to C point, now leave this Microcell, then mobile terminal starts to be switched to other Microcell again, thus causes frequent switching problem.Too many hand off signaling will waste air interface and backhaul resources.And switch frequently and also can cause signaling overload and calling cutting off rate significant problem, the call of user is experienced poor.

This problem is particularly remarkable when mobile terminal high-speed motion, such as, have the train of many passengers or bus rapid transit when crossing along the street of the block covered by grand and Microcell.

Such as, but under this kind of scene, temporary respite switching in indiscriminate ground also can be with the problem of serving, and may bring the problem such as throughput degradation and cutting off rate rising.

Therefore, this area can effectively utilize the high-speed transfer of little community in the urgent need to a kind of and do not cause the changing method switched frequently.

Summary of the invention

For this reason, the present invention proposes the auxiliary moving administrative mechanism of position-based information, its trial uses such as position, speed (to those skilled in the art, speed is the function of position, and therefore speed can regard the one of positional information as), the positional information of parameter that location factor and/or the position influence factor etc. are relevant to position helps switch.Particularly useful in this deployment situation mixed at micro--macrocell.

According to an aspect of the present invention, a kind of method for mobile terminal being switched to Target cell is provided, described Target cell comprises Microcell, and the method can comprise: determine the positional information of mobile terminal in base station for each target candidate community in Active Set; And based on the positional information of described mobile terminal with reference to the pilot frequency intensity decision-making of the target candidate community in described Active Set to the switching of described target candidate community.

Preferably, described steps in decision-making may further include: predict whether described mobile terminal is in the zone line of the target candidate community in described Active Set; If predict that described mobile terminal is in the zone line of described target candidate community, then comparison prediction is in the pilot frequency intensity of the described target candidate community of its zone line; And based on the pilot frequency intensity of described target candidate community, decision-making is from described former Serving cell to the switching of target candidate community with the strongest pilot frequency intensity.

Preferably, the step that whether the described mobile terminal of described prediction is in the zone line of target candidate community can comprise further: the position of predicting described mobile terminal after predetermined residence time; Determine the relative position of described mobile terminal and target candidate community after described residence time; And determine whether described mobile terminal is in the zone line of target candidate community after predetermined residence time based on this relative position.

Preferably, describedly determine that the step of the relative position of described mobile terminal and target candidate community can comprise further: the relative position determining described mobile terminal and target candidate community based on following equation: L _f=L/R, wherein, L _ffor location factor, L is the distance between mobile terminal and target BS, and R is the radius of target candidate community.

Preferably, determine that the step of the relative position of described mobile terminal and target candidate community can comprise further: primary importance and the second place of determining described mobile terminal; Calculate the speed of described mobile terminal; 3rd position of prediction described mobile terminal after predetermined residence time; And determine the relative position of described mobile terminal and target candidate community based on above-mentioned formula for described 3rd position.

Preferably, predict that the step whether described mobile terminal is in the zone line of target candidate community can comprise further: the position determining described mobile terminal; Calculate the speed of described mobile terminal; The ratio of the diameter of more described speed and described target candidate community and the minimum residence time of this community; And determine whether described mobile terminal is in the zone line of target candidate community after predetermined residence time based on described comparative result.

Preferably, the described step determining whether described mobile terminal is in the zone line of target candidate community after predetermined residence time can comprise further: if described location factor is greater than predetermined threshold or described speed is greater than above-mentioned ratio, then determine beyond the edge that described mobile terminal is in target candidate community or cell coverage area; Otherwise, determine that described mobile terminal is in the zone line of target candidate community.

Preferably, described decision-making can comprise further to the switch step of described target candidate community: for the positional information determination position influence factor of the described target candidate community in Active Set based on described mobile terminal, the described position influence factor characterizes the influence degree of position to pilot frequency intensity of mobile terminal; The relatively pilot frequency intensity of each target candidate community and the difference of the position influence factor; And decision-making is switched to the target candidate community of the difference with maximum pilot frequency intensity and the position influence factor.

Preferably, described method also can comprise: the message sending the location-based pilot frequency intensity adjustment information of the described mobile terminal comprised for the target candidate community in Active Set in base station to described mobile terminal, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal.

According to other aspect of the present invention, provide a kind of method for mobile terminal being switched to Target cell, can comprise: receive at described mobile terminal place from base station, pointer is to the message of the location-based pilot frequency intensity adjustment information of the target candidate community in Active Set, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal, characterizes the influence degree of position to pilot frequency intensity of mobile terminal; And based on mobile terminal decision-making described in described pilot frequency intensity adjustment information from described former Serving cell to the switching of target candidate community.

Preferably, former Serving cell described in described decision-making may further include to the step of the switching of target candidate community: be switched to the target candidate switching cell with maximum comprehensive pilot frequency intensity from former Serving cell based on comprehensive pilot frequency intensity maximal criterion.

According to other aspect of the present invention, also provide a kind of base station, it can comprise: determining unit, for determining the position of mobile terminal; Computing unit, for calculating the positional information comprising location factor or speed of described mobile terminal; And decision package, for the switching to described target candidate community of assisting with reference to the pilot frequency intensity decision-making position-based of the target candidate community in described Active Set based on the positional information of described mobile terminal.

Preferably, described computing unit also can be configured to calculate the original position factor of described mobile terminal to determine beyond the edge whether described mobile terminal is in Serving cell, source or cell coverage area.

Preferably, described computing unit is also configured the size of more described speed and cell diameter and the ratio of predetermined service time to predict whether described mobile terminal is in the zone line of target candidate community after predetermined service time.

According to other aspect of the present invention, a kind of mobile terminal is also provided, comprise: receiving element, for receiving pointer from base station to the message of the location-based pilot frequency intensity adjustment information of the target candidate community in Active Set, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal, characterizes the influence degree of position to pilot frequency intensity of mobile terminal; Resolution unit, for extracting the location-based pilot frequency intensity adjustment information for the target candidate community in Active Set from described message; Decision package, for the switching to described target candidate community of assisting based on described pilot frequency intensity adjustment information decision-making position-based.

According to other aspect of the present invention, also comprise a kind of computer program, it has computer-readable instruction, when it runs on the computing device, is configured to perform method as above.

In an embodiment of the present invention, by introducing the auxiliary handover mechanism of position-based information, the frequent switching problem that may occur can be suppressed, and make full use of the high speed data transfer of Microcell, can also reduce owing to too much switching the call drop that causes to improve Consumer's Experience, even can also carry out load balance based on the positional information of such as speed, such as high speed mobile terminal will have more multimachine and can be served by macrocell, and low speed mobile terminal will more may be served by Microcell.

Accompanying drawing explanation

According to the following specifically describes of carrying out by reference to the accompanying drawings, clearly exemplary embodiment will be understood.Fig. 1-10 represents non-limiting, exemplary embodiment, wherein:

Fig. 1 is exemplified with typical many picocell deployment in macrocell of the prior art;

Fig. 2 mixes deployment situation exemplified with typical Microcell of the prior art and macrocell;

Fig. 3 is exemplified with the schematic diagram carrying out switching in situation shown in fig. 2;

Fig. 4 is exemplified with the physical model of location factor according to an embodiment of the invention;

Fig. 5 is exemplified with the flow chart carrying out location aided rebroadcast handover decisions according to an embodiment of the invention in a communication network.

Fig. 6 is exemplified with assisting the flow chart of the decision-making of switching in base station side at the enterprising line position in the basis of position judgment according to an embodiment of the invention;

Fig. 7 is exemplified with the flow chart carrying out location aided rebroadcast switchover policy of the position-based factor according to an embodiment of the invention;

Fig. 8 is exemplified with the flow chart carrying out location aided rebroadcast switchover policy according to an embodiment of the invention based on speed;

Fig. 9 is exemplified with the flow chart carrying out the decision-making of location aided rebroadcast switching according to an embodiment of the invention at base station side position-based factor of influence;

Figure 10 is exemplified with the flow chart performing the location aided rebroadcast handover decisions that mobile terminal is assisted under EVDO environment according to an embodiment of the invention according to an embodiment of the invention in a communications system;

Figure 11 is exemplified with the block diagram of base station according to an embodiment of the invention; And

Figure 12 is exemplified with the block diagram of mobile terminal according to an embodiment of the invention.

Embodiment

More intactly embodiments of the invention are described referring now to accompanying drawing, shown in it some but and the not all embodiment of the present invention.Certainly, the present invention by many multi-form realizations, and should not be construed the restriction to the embodiment set forth here; On the contrary, provide these embodiments, thus the present invention will meet the legal requirements be suitable for.Wherein like numerals will refers to analogous element.

It shall yet further be noted that in some alternatives, the function/behavior of proposition may with from different the occurring in sequence shown in accompanying drawing.Such as, in fact two figure continuously can perform substantially simultaneously, or can sometimes perform with reverse order, and this is according to the function/behavior related to.

Unless the contrary is defined, all terms used herein (comprising technology and scientific terminology) have the identical meanings understood with exemplary embodiment those skilled in the art.Should also be understood that term (defining in such as general dictionary) should be interpreted as having the implication that in the environment with association area, their implication is consistent, and do not explain, unless clearly defined here from idealized or undue formalization aspect.

Representing according to the symbol of the operation of the data bit in computer storage to provide part of the present invention and relevant details to describe with software or algorithm.These describe and represent is that those skilled in the art effectively pass on them the means of action to others skilled in the art whereby.As term used herein, and normally used as it, what algorithm can think to cause the step of expected result is in harmony sequence certainly.Step is those steps needing physical operations physical quantity.Usually, although unnecessary, this tittle adopts the form of the optical, electrical or magnetic signal that can store, transmit, combine, compare and handle.Often prove easily, in order to general in principle, these signals are called bit, value, element, symbol, word, item, numeral etc.

In the following description, with reference to can be used as program module or functional processing (comprises routine, program, object, assembly, data result etc., it performs particular task or realize particular abstract data type, and existing hardware can be used to realize at existing network unit or Controlling vertex place) behavior of operation that realizes and symbol represent (such as in a flowchart) to describe exemplary embodiment.Such existing hardware can comprise one or more CPU (CPU), digital signal processor (DSP), application-specific integrated circuit (ASIC), field programmable gate array (FPGA) computer etc.

But should remember, all these are relevant to suitable physical amount with similar terms, and be only be applied to this tittle facilitate label.Except non-specifically is set forth, or from discussion clearly, such as the term of " process " or " calculating " or " determination " or " decision-making " etc. refers to behavior and the process of computer system or similar electronic computing device, in the RS of its operation computer system be expressed as physics, amount of electrons data and be transformed to other data of the similar physical quantity be expressed as in the such information-storing device of computer system memory or register or other, transmission or display device.

It shall yet further be noted that typically encode in the aspect of software simulating of the present invention on certain program recorded medium, or realize on the transmission medium of some types.Program recorded medium can be (such as the compact disk read-only memory or " CDROM ") of magnetic (such as floppy disk or hard disk drive) or light, and can be read-only or arbitrary access.Similarly, transmission medium can be twisted-pair feeder, coaxial cable, optical fiber or other suitable transmission mediums more known in the art.The present invention is not subject to the restriction of these aspects of any given scheme.

Existing changing method is based on the pilot frequency intensity detected from mobile terminal, and this value is by the E of all available multipath components in mobile terminal joint account search window _c/ I _oand obtain.Such as, under the environment based on EVDO technology, if mobile terminal measures the E of community B on forward link _c/ I _obe greater than the E of community A _c/ I _o, this terminal can attempt asking the data from community B, then mobile terminal carrys out report pilot strength by routing update message (RouteUupdateMessage in such as EVDO is called for short RUM message).Can also by the load balancing feature introduced by EVDOrev.C standard (3GPP2C.S0024-Cv1.0), reference signal quality and business load state carry out handover decisions.As mentioned above, under macrocell and Microcell mix deployment situation, mobile terminal fast moving can produce the problems such as frequent switching.

The problems such as the frequent switching disposed under situation are mixed at macrocell and Microcell in order to solve, in an embodiment of the present invention, propose location aided rebroadcast handover mechanism, its basic conception is by introducing the positional information relevant with position such as location factor (characterizing the relative position of mobile terminal and target candidate community), come relative position and pilot frequency intensity, thus can determine whether be switched to target candidate Microcell in conjunction with pilot frequency intensity position-based information.

In an embodiment of the present invention, for simplicity, for base station (BS) and mobile terminal (MS), the operation that decision-making location aided rebroadcast within a wireless communication network switches is described.But those skilled in the art should understand that, in different communication networks, the title that base station is corresponding different, such as, in the EVDO communication network defined in third generation partner program 2 (3GPP2), entity corresponding to base station is called AN (Access Network), and in the WCDMA defined in third generation partner program (3GPP) and LTE communication network, entity corresponding to base station is called NodeB and eNodeB, is in this collectively base station.

Fig. 4 is exemplified with the physical model of location factor according to an embodiment of the invention.In an embodiment of the present invention, as shown in Figure 4 A, in order to solve the problem, location factor (L is introduced _f), it is included in the positional information of the mobile terminal under base station coverage, can characterize the relative position of mobile terminal and community, be defined as follows:

L _f＝L/R(1)

Wherein L is the relative distance of the base station of mobile terminal and community, and R is radius of society.

As shown in Figure 4 B, in an embodiment of the present invention, can setting position threshold alpha.

If L _f<=α, then determine that travelling carriage is in the zone line (shown in blank region) of cell/section, and have more trend to be served by current area/sector.

If L _f> α, can determine outside the fringe region (shown in shade region) that travelling carriage is in community or community, and by current area/sector service quality and non-optimal.Especially, if L _f> 1, then mean that travelling carriage has left the coverage of community.

In an embodiment of the present invention, α is configurable value, and such as its scope can between 70% to 90%.

As shown in Figure 4 C, mobile terminal is that (coordinate is X1 to L1 from position, Y1) A point moves into place and is set to L2 (coordinate is X2, Y2) B point, and after m second, move to C point with this direction, m can be the predetermined residence time of community, such as minimum residence time, the minimum time that this minimum residence time Zhi Gai community must stop.This parameter can configure in a base station, will be described in detail below.

In order to know for the purpose of brief description, the movement of mobile terminal in this community can be characterized by linear uniform motion.Assuming that base station obtains coordinate L1 and L2 that the time interval is two position A and B of T, estimate the moving velocity vector of mobile terminal by following formula:

\overset{&RightArrow;}{V} = \overset{&RightArrow;}{D} (L 1, L 2) T - - - (2)

At this it is the displacement vector of A to B.

Then C point position coordinates L3 can by as follows predict:

L 3 = m \overset{&RightArrow;}{V} + L 2 - - - (3)

Can predict by adopting above-mentioned location factor whether this mobile terminal is in this community place after predetermined residence time such as minimum residence time.

Such as, the new position L3 predicted is obtained according to formula (3), by the distance of L3 coordinate and target candidate switching cell base station center position coordinates, obtain the relative distance L between it, calculated the L of target candidate switching cell by formula (1) _f, and compared with threshold alpha, if be greater than α, then after showing this time, mobile terminal will be in the edge of this community or leave this community.

In a further embodiment, the positional information of such as speed can also be introduced.In order to know for the purpose of brief description, the movement of mobile terminal in this community can be characterized by linear uniform motion.By determining mobile terminal at least twice position at certain time intervals, the speed of this mobile terminal can be determined.

But, it will be understood by those skilled in the art that any motion mode of mobile terminal in cellular cell is all possible, can use location information, according to the speed of existing physics and geometric knowledge determination mobile terminal.

So for those skilled in the art, if this speed V is greater than covering diameter (getting the maximum span of coverage at this) 2R of this community and the ratio of the predetermined residence time such as minimum residence time m in this community, then can be understood as this mobile terminal after this residence time and will shift out this community.Therefore speed also can characterize the relative position of mobile terminal and community to a certain extent.

To those skilled in the art, such as minimum residence time m is by default for the predetermined residence time of community, if mobile terminal is wanted to be switched to Microcell, it must at least stop m second.The determination of this value is relevant to the handoff time (such as EVDO community is to the switching of LTE community) of the handoff time (switching such as between EVDO system different districts) of identical systems and different system, can also be relevant to index requests such as the cutting off rate of system, signalling loads designs.

Assuming that be t during switching, then make m=nt, wherein n is configurable value.Such as, only supposing under the prerequisite that minimum residence time is relevant to handoff time, if pre-300 milliseconds at last of switching time, and n is set as 10, then m=3 second.

In an embodiment of the present invention, a kind of positional information being called the position influence factor is also introduced.Be similar to the adjusted value relative to load parameter (LoadingAdjust) (see 3GPP2C.S0024-Cv1.0) under non-load balanced case, the position influence factor in the embodiment of the present invention characterizes the influence degree of location parameter to pilot frequency intensity of mobile terminal.Due to the sign E of pilot frequency intensity _c/ I _ocorresponding with SNIR (ratio of signal and interference plus noise, is called for short signal to noise ratio in the present invention), in an embodiment of the present invention, this pilot frequency intensity can use signal to noise ratio, and namely SINR represents.In an embodiment of the present invention, this position influence factor can be the adjusted value (that is, comprehensive pilot frequency intensity can be SINR-PositionAdjust) of pilot frequency intensity relative to location parameter, and unit is dB.

Location factor L _fthe method being mapped as the PositionAdjust in units of dB can be:

PositionAdjust＝b＊lg(L _f)(4)

Wherein b is positive integer, and suggestion value is between 1 to 30.

Such as: position is 100 meters apart from target BS distance, and the radius of target BS is 50 meters, if get b=20, then location factor is: 20lg (100/50)=6dB.

In an embodiment of the present invention, can also setting position factor of influence by the following: in Microcell, assumed position factor of influence max threshold is 5dB.Then method to set up can be: if L _f> α, then PositionAdjust=5dB; Otherwise, PositionAdjust=0dB.This simple mapping method can avoid location factor excessive for the Decision Making Effect switched by restriction site factor of influence max threshold.

In an embodiment of the present invention, preferably, this parameter can be the adjusted value (that is, comprehensive pilot frequency intensity is SINR-LoadingAdjust-PositionAdjust) relative to load parameter and location parameter of signal to noise ratio.

It will be understood by those skilled in the art that any can the method for calculating location factor of influence all can being applied in embodiments of the invention, these are only illustration, embodiments of the invention are not limited to above-mentioned example.

In an embodiment of the present invention, a kind of method for mobile terminal being switched to Target cell being provided, can comprising: determine the positional information of mobile terminal in base station for each target candidate community in Active Set; And based on the positional information of described mobile terminal with reference to the pilot frequency intensity decision-making of the target candidate community in described Active Set to the switching of described target candidate community.

In an embodiment of the present invention, preferably, described decision-making can comprise further to the switch step of described target candidate community: predict whether described mobile terminal is in the zone line of the target candidate community in described Active Set; If predict that described mobile terminal is in the zone line of described target candidate community, then comparison prediction is in the pilot frequency intensity of the described target candidate community of its zone line; And based on the pilot frequency intensity of described target candidate community, decision-making is from described former Serving cell to the switching of target candidate community with the strongest pilot frequency intensity.

In an embodiment of the present invention, preferably, described decision-making comprises further to the switch step of described target candidate community: for the positional information determination position influence factor of the described target candidate community in Active Set based on described mobile terminal, the described position influence factor characterizes the influence degree of position to pilot frequency intensity of mobile terminal; The relatively pilot frequency intensity of each target candidate community and the difference of the position influence factor; Decision-making is switched to the target candidate community of the difference with maximum pilot frequency intensity and the position influence factor.

Fig. 5 is exemplified with the flow chart of the handover decisions of position-based information in a communication network according to an embodiment of the invention.Such as, assuming that travelling carriage is wanted such as, to be switched to cell/section B (target cell/sector, Microcell) from cell/section A (service cell/sector, source, macrocell).As shown in Figure 5, in step S501, event triggering mobile terminals occurs and measures, these events such as pilot measurement time timer expires or activates pilot set change etc.

Next, in step S503, when mobile terminal pilot tone change detected thus to occur some timer in the increase and decrease of pilot tone in Active Set or base station expire and trigger routing update measure request (such as routeupdaterequest) etc., each base station pilot intensity parameters that mobile terminal measures to base station repeats terminal.In different networks, dissimilar message can be used report.Such as, under EVDO environment, travelling carriage uses routing update RUM message to come to its measurement result of base station repeats.The form of this message will be described in detail below.

In step S505, the positional information of mobile terminal is determined in base station, can comprise in this positional information any information or parameter that position, location factor, speed or the position influence factor etc. associate with position.

In an embodiment of the present invention, determine that the position of mobile terminal can adopt the various known method be suitable for future, known method such as commonly use global position system GPS technology, signal strength signal intensity, time-based method (time of advent and the time of advent poor) and the time of advent difference and round-trip delay method etc.Brief description is as follows:

1. global position system GPS technology GPS is satellite-based navigation system.Gps receiver must lock onto the signal of at least three satellites to calculate 2D position (longitude and latitude).By visible 4 or more satellites, receiver can determine the 3D position (longitude, latitude and height) of user.

2. signal strength signal intensity uses the radio position finding radio directional bearing of signal strength signal intensity to be the localization method using the Mathematical Modeling of known description strength retrogression with the change of distance known.Because the measurement of signal strength signal intensity provides the range estimation between terminal and BS, thus terminal must be positioned at multiple BS be the center of circle, with the intersection point of multiple survey terminal multiple circumference that are radius to the estimated distance of each BS.

Such as, RUM message in EVDO comprises the pilot frequency intensity of multiple base station BS.Therefore, the position obtaining mobile terminal by signal strength signal intensity is possible.But the impact of the randomness due to multipath fading, uses this position estimation method accuracy under urban environment lower.

3. time-based method: the time of advent (ToA) and the time of advent poor (TDoA)

The method based on estimate to be sent by terminal and the ToA of signal that receives at multiple BS or at the TDoA of multiple BS to the reference signal received.

In ToA method, the distance between terminal and BS is by finding that the propagation time of the paths between terminal and BS measures.Geometrically mobile terminal must be in center BS, radius be the spacing of terminal and BS circumferentially.If there are at least three BS to receive this terminal signaling, the position of MS is provided by three circular common factors.

In TDoA method, the difference of the time of advent is used to estimate terminal location by two or more neighbor bss and the difference time of advent with reference to BS Received signal strength.Due to the track that hyperbola is the point being definite value with the absolute value of the difference of two distances of fixing a point in plane, if now the known time of advent poor, terminal track must be on the hyperbola of constant time difference of the arrival of two BS, and its focal length is at two BS places.If there are three BS to receive the signal of this terminal, then base station can measure two time differences.Therefore the position of mobile terminal is at two groups of hyp common factor places.Therefore need at least 3 paths to use TOA/TDOA method.

Contain the multiple pilot phase offset information measured from mobile terminal in such as, RUM message in EVDO, base station demodulates chip also can obtain more accurate signal and arrive phase deviation, and therefore TDoA location method is also possible.

Especially, for EVDO system, in RUM message, comprise multiple information relevant to location, such as: reference pilot is biased, reference pilot intensity, and each non-reference pilot phase offset and non-reference pilot frequency intensity etc.Base station can obtain the TDoA with reference base station by decoding RUM.

Can operate as follows: first each BS, according to the RUM message received, calculates respective pilot offset.Due in CDMA2000 and EVDO system, bit rate is per second 1.2288 million, and the minimum interval of pilot offset is 64 sections (chip), and the length of each section is 244 meters, and time span was 813.8 nanoseconds.Optional pilot offset is (totally 512) between 0 and 511, for reducing presence of intercell interference, isolated by configuration pilot increment (PilotIncrement).If such as pilot increment is 3, and PilotPNPhase is 237, then its PN is biased can be:

PilotPN＝floor[mod(PilotPNPhase+32＊PilotIncrement，512＊64)/(64＊PilotIncement)]＊PilotIncement(5)

Wherein floor is lower bracket function, and mod is remainder function.After substitution, PilotPN=3 can be obtained.

Known reference pilot tone (BS1) and non-reference pilot tone (BS2) phase bias, the difference Diff (unit is chip) of the one-way propagation time of the distance of terminal and BS2 and terminal and BS1 can be calculated as follows:

Diff＝(PilotPNPhase-ReferencePilotPN＊64)-64＊(PilotPN-ReferencePilotPN)(6)

Wherein, ReferencePilotPN is the PN biased (unit is 64chip) of reference pilot BS1, can carry in RUM message.PilotPNPhase is then the pilot frequency deviation (unit chip) of non-reference pilot tone BS2.And PilotPN is calculated according to formula (5) by PilotPNPhase and obtains.This value is multiplied by 244 both can obtain range difference (unit rice), and it is poor that the time (813.8 nanosecond) that this value is multiplied by each chip then obtains the time of advent, i.e. TDoA (unit second).

In like manner can calculate the distance of terminal and BS1 and the TDoA of terminal and BS3.

Therefore, solving two hyp common factors can the position of computing terminal.

4. the time of advent poor (TDoA) and round-trip delay (RTD) method

Because mobile terminal reports its pilot frequency intensity recorded, if two base stations each measurement can obtain earliest arrival time and to obtain the time of advent poor, the track of terminal is in on the hyperbola of the constant time difference of the arrival of two BS, and its focal length is at two BS places.And one of them base station can calculate terminal to this base station time delay (such as can by mobile phone for measuring to PilotPNPhase deduct this base station configuration ReferencePN*64 obtain, for some baseband chip, CSM5500, CSM6800, CSM6850 etc. of such as Qualcomm also directly can read transmission delay from baseband chip).It is the center of circle that the position of terminal is positioned at BS, with terminal on the distance of the BS circle that is radius.By solving the common factor of hyperbola and circle, can the position of computing terminal.

Below exemplified with the example of certain routing update message RUM in EVDO network.In this message, terminal has measured three pilot tones, and the PN of reference pilot is biased to 424, and the reference PN phase place of other two pilot tones is 22247 and 228.By known above, after these three base stations receive this message separately, namely can calculate the position of base station according to the method for TDOA or RTD/TDOA.

Usually, for EVDO network, once obtain RUM, multiple base station is by using one at least above-mentioned 4 methods position obtaining mobile terminal.It will be understood by those skilled in the art that and anyly determine that the mode of mobile terminal locations all can be applicable in embodiments of the invention, more than enumerating is only the specific implementation of example and non exhaustive embodiments of the invention.

In an embodiment of the present invention, in this step, base station can also calculate location factor, the positional information such as speed or the position influence factor of the pilot tone concentrated for mobile terminal activating based on said method.

Next, in step 507, the decision-making that the location aided rebroadcast proceeding to target candidate community switches.

In an embodiment of the present invention, the decision-making that the location aided rebroadcast can implementing position-based information in base station side switches.

Fig. 6 is exemplified with assisting the flow chart of the decision-making of switching in base station side at the enterprising line position in the basis of position judgment according to an embodiment of the invention.As shown in Figure 6, in step S610, predict whether described mobile terminal is in the zone line of the target candidate community in described Active Set.

Fig. 7 is exemplified with the flow chart carrying out location aided rebroadcast switchover policy of the position-based factor according to an embodiment of the invention.As shown in Figure 7, in an embodiment of the present invention, the position-based factor can predict whether mobile terminal is in the zone line of the target candidate community in Active Set by operating as follows:

In step S710, the position of mobile terminal after predetermined residence time can be predicted.Such as, can suppose that mobile terminal is linear uniform motion, then can determine primary importance L1 and the second place L2 of the mobile terminal of certain hour interval T, then can calculate the speed of this mobile terminal according to as above formula (2).Then, the 3rd position L3 of mobile terminal after predetermined residence time can be predicted according to formula (3).

In step S720, the basis knowing position can be determined the relative distance of mobile terminal and target candidate community after this residence time.This can obtain according to Euclidean distance formula.

Afterwards, in step S730, determine whether described mobile terminal is in the zone line of target candidate community after predetermined residence time based on this relative distance.The location factor L of the mobile terminal for this target candidate community such as can be determined according to formula (1) _f.If this location factor is greater than predetermined threshold, then determine beyond the fringe region that this mobile terminal is in this target candidate community or cell coverage area; Otherwise, determine that this mobile terminal is in the zone line of this target candidate community.Thus the target candidate community of more suitable switching can be determined based on aforesaid operations.

Fig. 8 is exemplified with the flow chart carrying out location aided rebroadcast switchover policy according to an embodiment of the invention based on speed.As shown in Figure 8, in an embodiment of the present invention, can also predict whether mobile terminal is in the zone line of the target candidate community in Active Set based on speed by operating as follows:

In step S810, determine the position of mobile terminal.In an embodiment of the present invention, the position of mobile terminal can be determined as mentioned above.Afterwards, in step S820, can as on calculate the speed V of mobile terminal.Next, in step S830, compare the ratio of the diameter of this speed V and this target candidate community and the predetermined residence time (can be minimum residence time) of this community.

Finally, in step S840, whether result determination mobile terminal is in the zone line of target candidate community after predetermined residence time based on the comparison.In an embodiment of the present invention, such as, if V > is 2R/m, then after predetermined residence time, this mobile terminal will leave this target candidate community, or be in the edge of this community.Can avoid like this being switched to this target candidate community (such as Microcell).Otherwise, can determine that this mobile terminal will be in the zone line of this target candidate community.Thus the target candidate community of more suitable switching can be determined.

Turn back to Fig. 6 now, in step S620, the operation of step S610 is repeated until all carried out aforesaid operations to the target complete candidate cell in Active Set, to determine to predict the subset of the target candidate community being in its zone line for next the target candidate community in Active Set.In an embodiment of the present invention, pilot offset (such as PN_offset) can be passed through and identify target candidate community.Thus the zone line that whether can be in this target candidate community by prediction mobile terminal filters out some the target candidate community in the Active Set being not too applicable to switching.

Afterwards, in step S630, determine whether the subset of this target candidate community is empty.If be not empty, then proceed to step S640.

In step S640, for the target candidate community in this subset, compare its pilot frequency intensity.In an embodiment of the present invention, signal to noise ratio SINR can be compared.

Finally, in step S650, decision-making is from described former Serving cell to the switching of target handover cell.In an embodiment of the present invention, signal to noise ratio can be the Target cell that criterion selectes switching to the maximum, namely be switched to the target candidate community with the strongest pilot frequency intensity.

In an embodiment of the present invention, if the subset of this target candidate community is empty, namely mobile terminal is not in any target candidate community in Active Set after predetermined residence time, then proceed to step S660, in this step, can determine whether it is in the zone line of former Serving cell.In an embodiment of the present invention, similarly, the location factor of this mobile terminal can be determined according to formula (1), and the size of the comparison position factor and predetermined threshold determines whether mobile terminal is in the zone line of former Serving cell.

If NO, namely location factor is greater than predetermined threshold, then in step S670, decision-making mobile terminal will proceed to the switching of target candidate community.This also can be criterion to the maximum with signal to noise ratio and select switching target small area.In an embodiment of the present invention, the target candidate community with the strongest pilot frequency intensity can be determined according to the pilot frequency intensity of all target candidate communities in Active Set.Thus decision-making is switched to the target candidate community that this has the strongest pilot frequency intensity.

If YES, then do not switch, terminate in step S680 handover decisions process.

In an embodiment of the present invention, the decision-making of location aided rebroadcast switching can also be carried out by position-based factor of influence.In an embodiment of the present invention, can for the positional information determination position influence factor of the described target candidate community in Active Set based on described mobile terminal, the described position influence factor characterizes the influence degree of position to pilot frequency intensity of mobile terminal; The relatively pilot frequency intensity of each target candidate community and the difference of the position influence factor; Decision-making is switched to the target candidate community of the difference with maximum pilot frequency intensity and the position influence factor.

Fig. 9 is exemplified with the flow chart carrying out the decision-making of location aided rebroadcast switching according to an embodiment of the invention at base station side position-based factor of influence.As shown in Figure 9, in step S910, determine its position influence factor for each target candidate community in Active Set.As mentioned above, by quantizing location factor, determine the position influence factor.

In step S920, combine former pilot frequency intensity and the position influence factor, obtain the comprehensive pilot frequency intensity of each candidate target cells.In an embodiment of the present invention, this parameter can be SINR-PositionAdjust.In an embodiment of the present invention, it is also conceivable to the situation of load, if consider situation and the loading condition of the terminal of network simultaneously, then can obtain comprehensive pilot frequency intensity is SINR-LoadingAdjust-PositionAdjust.Based on the EVDO network optimization standardization of load balancing, usual LoadingAdjust can adopt forward direction non-empty queue number to characterize (after such as taking the logarithm, unit is dB), specifically refer to 3GPP2C.S0024-Cv1.0, its full content is incorporated herein by reference.

Finally, in step S930, carry out the decision-making of location aided rebroadcast switching.In an embodiment of the present invention, criterion can be to the maximum with comprehensive pilot frequency intensity and select switching target small area.Switch as Target cell by selecting the target candidate community with maximum comprehensive signal to noise ratio in the comprehensive signal to noise ratio from each target candidate community in Active Set.

Finally, turn back to Fig. 5, in step S509, terminate this process.

In an embodiment of the present invention, base station can indicate whether to switch mobile terminal by arranging switching indication parameter.Such as in EVDO system, base station can determine whether by the value arranging DRCLock switching mobile terminal.If the DRCLock of target BS is set to 1, then represents and allow to be switched to this target BS.If the DRCLock of target BS is set to 0, then represents and do not allow to be switched to this target BS.

In an embodiment of the present invention, mobile terminal can also be carried out and assist handover decisions.As mentioned above, its position influence factor can be determined in base station side for each target candidate community in Active Set, this position influence factor position-based factor and generating.This position influence factor characterizes the degree of the location-based adjustment to pilot frequency intensity, therefore also can be described as pilot frequency intensity adjustment information in an embodiment of the present invention.The message of the pilot frequency intensity adjustment information comprised for each target candidate community Active Set can be sent in an embodiment of the present invention to mobile terminal, to notify mobile terminal from base station.

In an embodiment of the present invention, additionally provide a kind of method for mobile terminal being switched to Target cell, this Target cell can be Microcell.The method can comprise: receive at described mobile terminal place from base station, pointer is to the message of the location-based pilot frequency intensity adjustment information of the target candidate community in Active Set, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal, characterizes the influence degree of position to pilot frequency intensity of mobile terminal; And based on mobile terminal decision-making described in described pilot frequency intensity adjustment information from described former Serving cell to the switching of target candidate community.

In an embodiment of the present invention, criterion can be to the maximum to determine switching target small area with comprehensive pilot frequency intensity like the Decision Classes of this switching, thus be switched to the target candidate switching cell with maximum comprehensive pilot frequency intensity from former Serving cell.

When only considering position influence, in an embodiment of the present invention, comprehensive pilot frequency intensity (also referred to as comprehensive pilot frequency intensity parameter) can be SINR-PositionAdjust.In an embodiment of the present invention, it is also conceivable to the situation of load, consider situation and the loading condition of the terminal of network at the same time, comprehensive pilot frequency intensity parameter can be SINR-LoadingAdjust-PositionAdjust.The process of this and base station side is similar, does not repeat them here.

In an embodiment of the present invention, the LoadInformation message in EVDO system can be utilized to carry pilot frequency intensity adjustment information, to transmit positional information to mobile terminal, carry out handover decisions.

As shown in Table 1, broadcast load information is carried out by Loadinformation message in base station.The structure of this message as shown in following table one, see 3GPP2C.S0024-Cv1.0:

Table one

Wherein:

In MessageID field, it is 0x02 that base station can arrange this field.

In LoadingAdjust field, it be unit is that the unsigned number of 0.5dB is to represent the adjustment of load of this sector that base station can arrange this field.In an embodiment of the present invention, in order to carry positional information, it is LoadingAdjust+PositionAdjust that base station can arrange this field, and wherein PositionAdjust is the result (unit dB) (the such as position influence factor) after quantizing location factor.

In NeighborCount field, base station can arrange the number that this field is the adjacent sectors in this message.

In NeighborSectorLoadingAdjust field, it be corresponding with adjacent sectors, unit is that the unsigned number of 0.5dB is to represent the adjustment of load of this sector that base station can arrange this field.In an embodiment of the present invention, in order to carry positional information, it is NeighborSectorLoadingAdjust+NeighborSectorPositionAdjust that base station can arrange this field, wherein NeighborSectorPositionAdjust is the result (such as, unit dB) after quantizing the location factor of adjacent sectors.The order of NeighborSectorLoadingAdjust field is identical with the order of the adjacent sectors information in SectorParameters message.

In Reserved field, it is 0 that base station can arrange this reserved field.Mobile terminal can ignore this field.

In an embodiment of the present invention, mobile terminal can measure E _c/ I _o, the comprehensive pilot frequency intensity parameter of each target candidate community therefore in Active Set is easily determined.Thus can determine that the auxiliary switching of executing location is carried out in the Target cell switched at mobile terminal side.

Be the flow process exemplifying the location aided rebroadcast handover decisions of assisting according to the execution mobile terminal of communication system of the present invention below with EVDO environment.As shown in Figure 10, in step S101, there is trigger event triggering mobile terminals and carry out measure and transmit message.

In an embodiment of the present invention, the auxiliary handover mechanism of position-based information can be operated in activation switching or free time switching in.But it is more meaningful for the switching activated.In the switching activated, base station will frequently receive the RUM of mobile terminal.In certain embodiments, base station periodically will send Trigger message, and the AttributeOverride message of the pilot threshold sending RUMrequest message or have amendment is passed through in such as base station, trigger travelling carriage and send RUM message.

In step S102, after receiving these Trigger message, mobile terminal will with RUM message response.As implied above, in RUM message, contain the multiple pilot frequency deviation information detected from mobile terminal, therefore, this message can be used for location-based service.

In step S103, base station decodes RUM message, record Ec/Io, and utilize two the nearest RUM message received recently to be obtained the position of mobile terminal by one of above-mentioned technology, and to positional informations such as the location factor of the pilot tone calculating mobile terminal in the Active Set of mobile terminal, speed or the position influence factors.In an embodiment of the present invention, if definition mechanism makes the mobile terminal of activation send the RUM in cycle every the such as 2 seconds scheduled time, then base station can after using RUM message to obtain the position of mobile terminal the motion track of tracking mobile terminal.As mentioned above, by two continuous print RUM message, base station can obtain speed and the direction of mobile terminal.

In step S104, the position after predetermined residence time is predicted in base station.In an embodiment of the present invention, this can by said method such as realize.

At S105, location factor, speed or the position influence factor etc. in L3 position can also be determined for each target candidate community in Active Set.Quantification in units of dB is carried out to the location factor of L3 position, the position influence factor.Can quantize according to as above method.In an embodiment of the present invention, the mode that can quantize arbitrarily location factor can be adopted.

In step S106, base station can arrange pilot frequency intensity adjustment information in Loadinformation message, and broadcasts this Loadinformation message to mobile terminal.

In step S107, mobile terminal receives this message, extracts the pilot frequency intensity adjustment information of each target candidate community in Active Set, performs handover decisions based on this pilot frequency intensity adjustment information.In an embodiment of the present invention, decision-making is maximum according to being comprehensive pilot frequency intensity such as SINR-LoadingAdjust-PositionAdjust or SINR-PositionAdjust.

Under same idea of the present invention, provide a kind of base station, it can assist handover decisions by enforcing location.In an embodiment of the present invention, this base station can comprise: determining unit, for determining the position of mobile terminal; Computing unit, for calculating the positional information comprising location factor, speed or the position influence factor of described mobile terminal; And decision package, for the switching to described target candidate community of assisting with reference to the pilot frequency intensity decision-making position-based of the target candidate community in described Active Set based on the positional information of described mobile terminal.

In an embodiment of the present invention, described computing unit can be implemented as the part or all of operation in Fig. 5-10, such as determine described mobile terminal whether be in after predetermined residence time target candidate community zone line, for the positional information determination position influence factor etc. of the described target candidate community in Active Set based on described mobile terminal.

Figure 11 is exemplified with the structured flowchart of the base station 100 of the enforcement handover decisions according to the embodiment of the present invention.Device 100 (particularly processor) can be configured to realize the operation described in above generality and function, the process such as the control of such as calling out and the control of switching.In addition, device 100 (particularly processor) can be configured to perform about some described in Fig. 5-10 or all operations.

Similarly, device 100 can comprise processor, memory devices and communication interface or communicate with.Similar to the above, processor can be embodied as various device, comprise such as, microprocessor, coprocessor, controller or comprise other treatment facilities various of integrated circuit (such as ASIC (application-specific integrated circuit (ASIC)), FPGA (field programmable gate array) or hardware accelerator).About the processor as FPGA, ASIC etc., this processor can be the hardware being configured to the operation performing processor described here especially.In the exemplary embodiment, processor is configured to perform the instruction that stores in memory devices or the addressable instruction of processor.

In one exemplary embodiment, one or more processes described here realize by the computer program comprising code instructions.Thus, the code instructions realizing process described here by device (such as device 100 and/or 200) memory device for storing or be stored thereon, and to be performed by processor.Can understand, code instructions so arbitrarily can be loaded on computer, processor or other programmable devices (such as processor, memory devices), to generate machine, it comprises the device for the function of specifying in the square frame of realization flow figure, step or operation.In some exemplary embodiments, these code instructions also store in a computer-readable storage medium, its instruct computer, processor or other programmable devices are to run by ad hoc fashion, thus the instruction stored in computer-readable recording medium generates goods, it also provides the device of the function of specifying in the square frame of realization flow figure, step or operation.Code instructions also can be loaded on computer, processor or other programmable devices, to perform sequence of operations step on computer, processor or other programmable devices or by it, to generate computer implemented process, thus the instruction performed on computer, processor or other programmable devices provides the step of the function of specifying in the square frame of realization flow figure, step or operation.

In an embodiment of the present invention, as shown in figure 11, base station 100 can comprise: determining unit 102, for determining the position of mobile terminal; Computing unit 104, for calculating the positional information comprising location factor or speed of described mobile terminal; And decision package 106, for the switching to described target candidate community of assisting with reference to the pilot frequency intensity decision-making position-based of the target candidate community in described Active Set based on the positional information of described mobile terminal.

In an embodiment of the present invention, described computing unit 104 also can be configured to calculate the original position factor of described mobile terminal to determine beyond the fringe region whether described mobile terminal is in Serving cell, source or this cell coverage area.

Preferably, described computing unit 104 is also configured to prediction described mobile terminal after predetermined service time and whether is in the zone line of target candidate community.In an embodiment of the present invention, described computing unit 104 can be configured to the size of more described speed and cell diameter and the ratio of predetermined service time to predict whether described mobile terminal is in the zone line of target candidate community after predetermined service time.

Figure 12 illustrates and is arranged to according to each embodiment of the present invention the Exemplary mobile terminal 200 carrying out handover decisions in a communication network.Device 200 (particularly processor) can be configured to realize the operation described in above generality and function, the measurement of such as communication, signal quality and report.In addition, device 200 (particularly processor) can be configured to perform about some described in Fig. 5-10 or all operations.

In some exemplary embodiments, device 200 can be embodied as, or comprises the assembly for the computing equipment and/or communication equipment with wireless communication ability.Some example of device 200 comprises computer, server, mobile terminal (such as mobile phone, portable digital-assistant (PDA), beep-pager, mobile TV, game station, mobile computer, laptop computer, camera, video recorder, audio/video player, radio and/or global positioning system (GPS) equipment) or above-mentioned combination in any etc.In addition, device 200 can be configured to realize various aspects of the present invention described here, such as each illustrative methods of the present invention, wherein said method is by configure hardware and/or software, firmware or its realization such as processor (such as processor), computer-readable medium of combining.

Device 200 can comprise processor, memory devices and communication interface or communicate with.In addition, processor can be embodied as various device, comprise such as, microprocessor, coprocessor, controller or comprise other treatment facilities various of integrated circuit (such as ASIC (application-specific integrated circuit (ASIC)), FPGA (field programmable gate array) or hardware accelerator).About the processor as FPGA, ASIC etc., this processor can be the hardware being configured to the operation performing processor described here especially.In the exemplary embodiment, processor is configured to perform the instruction that stores in memory devices or the addressable instruction of processor.Processor can be configured to be convenient to such as by controlling control hardware that communication interface comprises and/or software via communication interface communication.

Memory devices can be configured to be stored in each information realizing relating in embodiments of the invention.Memory devices can be computer-readable recording medium, can comprise volatibility and/or nonvolatile memory.Such as, memory devices can to comprise on random access memory (RAM) (comprise dynamically and/or static RAM (SRAM)), sheet or under sheet cache memory and/or other.In addition, memory devices can comprise nonvolatile memory, it can be embedded into and/or removable, and can comprise such as read-only memory, flash memory, magnetic storage apparatus (such as hard disk, floppy disk, tape etc.), CD drive and/or medium, nonvolatile RAM (NVRAM) and/or other.Memory devices can comprise the cache memory section for temporary storaging data.Thus, some or all of memory devices can comprise within a processor.

In addition, memory devices can be configured to storage information, data, application, computer readable program code instruction etc., is provided for processor and device 200 performs each function according to an exemplary embodiment of the present invention.Such as, memory devices can be configured to buffering input data for processor process.In addition, or alternatively, memory devices can be configured to store the instruction performed by processor.

Communication interface can be that it is configured to from the network communicated with device and/or other equipment or module receive data and/or send data to it arbitrarily with the arbitrary equipment of the combination of hardware, computer program or hardware and software realization or device.Thus, communication interface can comprise such as, antenna, reflector, receiver, transceiver and/or support hardware, comprises for supporting and the processor of network service or computer program.

Communication interface can be configured to provide communication according to any wireless communication standard.Such as, communication interface can be configured to provide communication according to following standard: the second generation (2G) wireless communication protocol IS-136 (time division multiple access (TDMA)), GSM (global system for mobile communications), IS-95 (code division multiple access (CDMA)), the third generation (3G) wireless communication protocol (such as Universal Mobile Telecommunications System (UMTS), CDMA2000, wideband CDMA (WCDMA) and time division synchronous CDMA (TD-SCDMA)), 3.9 generations (3.9G) wireless communication protocol (such as evolved universal terrestrial radio access network (E-UTRAN)), forth generation (4G) wireless communication protocol, international mobile telecommunication senior (IMT-Advanced) agreement, Long Term Evolution (LTE) agreement (comprising LTE-Advanced) etc.

In an embodiment of the present invention, user terminal 200 as shown in figure 12 can comprise: receiving element 202, for receiving pointer from base station to the message of the location-based pilot frequency intensity adjustment information of the target candidate community in Active Set, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal, characterizes the influence degree of position to pilot frequency intensity of mobile terminal; Resolution unit 204, for extracting the location-based pilot frequency intensity adjustment information for the target candidate community in Active Set from described message; Decision package 206, for based on the switching of described pilot frequency intensity adjustment information decision-making to described target candidate community.It can be configured to perform some or all step as Fig. 5-10 or operation.

Obviously, by introducing location aided rebroadcast handover mechanism in embodiments of the present invention, exempting or inhibit the possible frequent switching problem caused by the mobility that Microcell covering radius is little or high, thus reducing over to switch the cutting off rate caused more, improving Consumer's Experience.In addition, by this mechanism, high speed mobile terminal will have more multimachine and can be served by macrocell, and low speed mobile terminal will more may be served by Microcell, achieves the load balancing based on speed.And the mobility information proposed in embodiments of the present invention also can be used for many location-based application.In addition, the location factor of proposition can also strengthen technology by other EVDO and use, such as Intelligent carrier management, distributed network scheduling (DNS) etc.Therefore, location aided rebroadcast changing method for picocell deployment and high mobility equipment very useful.

Although it should be appreciated by those skilled in the art that the embodiments of the invention illustrated as an example in this manual under the 3G background using EVDO, the handover mechanism of embodiments of the invention also can be applied in the system that other are suitable.

In an embodiment of the present invention, the square frame of flow chart, step or operation support the combination of the device for performing specific function, for perform the step of specific function combination, for performing the code instructions of specific function.Also can understand, in some exemplary embodiments, the square frame in one or more square frames of flow chart, step or operation and flow chart, being combined through of step or operation perform specific function or the computer system based on specialized hardware of step or the combination of processor or specialized hardware and code instructions and realize.

Of the present invention many amendments of setting forth here and other embodiments benefit from making those skilled in the art related to the present invention the instruction provided in above specification and relevant drawings.Therefore, can understand, the invention is not restricted to disclosed specific embodiment, and amendment and other embodiments are intended to comprise within the scope of the appended claims.In addition, although above specification and relevant drawings describe the exemplary embodiment in the environment of certain example combinations of parts and/or function, it should be understood that, the various combination of parts and/or function provides by alternative, and does not depart from the scope of claims.Thus, such as, as set forth in some claims those, also can imagine their various combination except those above clear and definite described parts and/or function.Although the particular term adopted here, they are only used as general and descriptive sense, the object not for limiting.

Claims

1., for mobile terminal being switched to a method for Target cell, comprising:

The positional information of mobile terminal is determined for each target candidate community in Active Set in base station; And

Based on the positional information of described mobile terminal with reference to the pilot frequency intensity decision-making of the target candidate community in described Active Set to the switching of described target candidate community;

Wherein said decision-making comprises further to the switch step of described target candidate community:

Predict whether described mobile terminal is in the zone line of the target candidate community in described Active Set;

If predict that described mobile terminal is in the zone line of described target candidate community, then comparison prediction is in the pilot frequency intensity of the described target candidate community of its zone line; And

Based on the pilot frequency intensity of described target candidate community, decision-making is from former Serving cell to the switching of target candidate community with the strongest pilot frequency intensity.

2. the method for claim 1, wherein predict that the step whether described mobile terminal is in the zone line of target candidate community comprises further:

The position of prediction described mobile terminal after predetermined residence time;

Determine the relative position of described mobile terminal and target candidate community after described residence time; And

Determine whether described mobile terminal is in the zone line of target candidate community after predetermined residence time based on this relative position.

3. method as claimed in claim 2, wherein determine that the step of the relative position of described mobile terminal and target candidate community comprises further:

The relative position of described mobile terminal and target candidate community is determined based on following equation:

L _f＝L/R

Wherein, L _ffor location factor, L is the relative distance of described mobile terminal and base station, and R is the radius of target candidate community.

4. the method for claim 1, wherein predict that the step whether described mobile terminal is in the zone line of target candidate community comprises further:

Determine the position of described mobile terminal;

Calculate the speed of described mobile terminal;

The ratio of the diameter of more described speed and described target candidate community and the predetermined residence time of this community; And

Determine whether described mobile terminal is in the zone line of target candidate community after predetermined residence time based on described comparative result.

5. method as claimed in claim 2, wherein:

Determine that the step of the relative position of described mobile terminal and target candidate community comprises further:

L _f＝L/R

Wherein, L _ffor location factor, L is the relative distance of described mobile terminal and base station, and R is the radius of target candidate community;

Predict that the step whether described mobile terminal is in the zone line of target candidate community comprises further:

Determine the position of described mobile terminal;

Calculate the speed of described mobile terminal;

Determine whether described mobile terminal is in the zone line of target candidate community after predetermined residence time based on described comparative result;

The described step determining whether described mobile terminal is in the zone line of target candidate community after predetermined residence time comprises further:

If described location factor is greater than predetermined threshold or described speed is greater than the diameter of described target candidate community and the ratio of the predetermined residence time of this community, then determine beyond the fringe region that described mobile terminal is in described target candidate community or cell coverage area;

Otherwise, determine that described mobile terminal is in the zone line of described target candidate community.

6. the method for claim 1, wherein said decision-making comprises further to the switch step of described target candidate community:

For the positional information determination position influence factor of the described target candidate community in Active Set based on described mobile terminal, the described position influence factor characterizes the influence degree of position to pilot frequency intensity of mobile terminal;

The relatively pilot frequency intensity of each target candidate community and the difference of the position influence factor;

Decision-making is switched to the target candidate community of the difference with maximum pilot frequency intensity and the position influence factor.

7. the method for claim 1, wherein also comprises:

Send the message of the location-based pilot frequency intensity adjustment information of the described mobile terminal comprised for the target candidate community in Active Set to described mobile terminal in base station, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal.

8., for mobile terminal being switched to a method for Target cell, comprising:

Receive at described mobile terminal place from base station, pointer is to the message of the location-based pilot frequency intensity adjustment information of the target candidate community in Active Set, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal, characterizes the influence degree of position to pilot frequency intensity of mobile terminal;

Based on mobile terminal decision-making described in described pilot frequency intensity adjustment information from former Serving cell to the switching of target candidate community;

9. a base station, comprising:

Determining unit, for determining the position of mobile terminal;

Computing unit, for calculating the positional information comprising location factor or speed of described mobile terminal; And

Decision package, for the positional information based on described mobile terminal with reference to the pilot frequency intensity decision-making of the target candidate community in Active Set to the switching of described target candidate community;

10. a mobile terminal, comprising:

Receiving element, for receiving pointer from base station to the message of the location-based pilot frequency intensity adjustment information of the target candidate community in Active Set, wherein said pilot frequency intensity adjustment information generates based on the positional information of described mobile terminal, characterizes the influence degree of position to pilot frequency intensity of mobile terminal;

Resolution unit, for extracting the location-based pilot frequency intensity adjustment information for the target candidate community in Active Set from described message;

Decision package, for based on the switching of described pilot frequency intensity adjustment information decision-making to described target candidate community;