CN104066166B

CN104066166B - A kind of time synchronization method and small base station

Info

Publication number: CN104066166B
Application number: CN201310093045.3A
Authority: CN
Inventors: 张兴炜; 万蕾; 马莎; 李强; 郑娟
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2013-03-21
Filing date: 2013-03-21
Publication date: 2018-03-09
Anticipated expiration: 2033-03-21
Also published as: CN104066166A; WO2014146601A1

Abstract

The embodiment of the invention discloses a kind of time synchronization method and small base station, and for avoiding when higher level's synchronization base station is not used to Timing Synchronization, small base station needs to re-start the problem of synchronisation source is searched for.The embodiment of the present invention includes：It is determined that first higher level's synchronization base station for Timing Synchronization；Determine at least one second higher level synchronization base station；If second higher level's synchronization base station is used for the alternative of Timing Synchronization, when first higher level's synchronization base station is not used to Timing Synchronization, synchronization is timed using second higher level's synchronization base station；If second higher level's synchronization base station is also used for Timing Synchronization, synchronization is timed using first higher level's synchronization base station and/or second higher level's synchronization base station.

Description

A kind of time synchronization method and small base station

Technical field

The present invention relates to technical field of communication, more particularly, to a kind of time synchronization method and small base station.

Background technology

In Long Term Evolution LTE (Long Term Evolution)-A Rel-12 versions, for the enhancing of hot spot region As a heat subject.Wherein, hot spot region is covered by the small base station (Pico eNB, Pico eNodeB) of multiple low-power Cap-shaped is into multiple small subzone networks (SCN, Small Cell Network).

Because small base station range is smaller than macro base station (MeNB, Macro Evolved NodeB), the user of service sets Standby (UE, User Equipment) quantity is also less than MeNB, thus can reduce the expense of pilot tone and control signaling.Add, Due to the UE negligible amounts of small base station service, sometimes even without the UE for needing offer service, and due to the work of small base station With being to improve throughput of system, equally need to ensure to cover rather than macro base station, thus consider to economize on electricity, small base station can be by Close or into sleep state, no longer service is provided for UE into dormant small base station.

In LTE time division duplexs (TDD, Time Division Duplex) and LTE FDDs (FDD, Frequency Division Duplex) in system, in order to reduce the interference of minizone, minizone needs precise synchronization.For no grand covering Scene, small base station need obtain Timing Synchronization be a relatively difficult thing.It is existing be used for Home eNodeB (HeNB, Home Evolved NodeB) the most frequently used synchronous method be network monitoring mechanism (NLM, Network Listening Mechanism).In NLM, small base station obtains synchronization using network monitoring from another base station, base station synchronous with the higher level Keep synchronous, need to forward from farther out by multiple nodes if small base station directly can not obtain synchronously from another base station Base station obtain it is synchronous；But during Timing Synchronization, when higher level's synchronization base station is not used to Timing Synchronization, small base Station needs the consuming regular hour to re-start the search of synchronisation source, and service can not be during this period of time provided for UE, and with small Base station can not also be timed the synchronous synchronisation source for obtaining stabilization for those base stations of higher level's synchronization base station.

The content of the invention

The embodiments of the invention provide a kind of time synchronization method and small base station, for avoiding when synchronous base station can not be used When Timing Synchronization, small base station needs to re-start the problem of synchronisation source is searched for.

In view of this, first aspect present invention provides a kind of time synchronization method, including：

It is determined that first higher level's synchronization base station for Timing Synchronization；

Determine at least one second higher level synchronization base station；

If the second higher level synchronization base station is used for the alternative of Timing Synchronization, when the first higher level synchronization base station can not During for Timing Synchronization, synchronization is timed using the second higher level synchronization base station；

If the second higher level synchronization base station is also used for Timing Synchronization, using the first higher level synchronization base station and/or The second higher level synchronization base station is timed synchronization.

In the first possible implementation of first aspect, if the second higher level synchronization base station is used for Timing Synchronization It is alternative, the second higher level synchronization base station based on following manner determine：

It is determined that it is second higher level's synchronization base station that base station synchronous with first higher level, which has the base station of identical synchronization level,；

Or determine that synchronization level highest base station is second higher level's synchronization base station；

Or determine that the maximum base station of signal intensity is second higher level's synchronization base station.

With reference to the first possible implementation of first aspect, in second of possible implementation, the determination Synchronization level highest base station is second higher level's synchronization base station, including：

If it is determined that when base station not synchronous with first higher level has the base station of identical synchronization level, it is determined that synchronous etc. Level highest base station is second higher level's synchronization base station；

The base station for determining that signal intensity is maximum is second higher level's synchronization base station, including：

If it is determined that base station not synchronous with first higher level has the base station of identical synchronization level or has multiple and institute When stating first higher level's synchronization base station has the base station of identical synchronization level, determine that the maximum base station of signal intensity is same for the second higher level Walk base station；Or

If it is determined that base station not synchronous with first higher level has the base station of identical synchronization level and has multiple synchronizations During grade highest base station, determine that the maximum base station of signal intensity is second higher level's synchronization base station.

With reference to the first possible implementation of first aspect, in the third possible implementation, if described Two higher level's synchronization base stations are used for the alternative of Timing Synchronization, and methods described also includes：

If the second higher level synchronization base station is not used to Timing Synchronization or the second higher level synchronization upgrading base station to work as During preceding higher level synchronization base station for Timing Synchronization, the determination mode based on the second higher level synchronization base station determines new alternative Higher level's synchronization base station.

In the 4th kind of possible implementation of first aspect, if the second higher level synchronization base station is used for Timing Synchronization It is alternative, methods described also includes：

If the first higher level synchronization base station base station synchronous with second higher level has the synchronization level differed, and institute When to state second higher level's synchronization upgrading base station be the higher level synchronization base station for being currently used in Timing Synchronization, adjust itself synchronization level and compare institute The low one-level of synchronization level of second higher level's synchronization base station is stated, and is controlled synchronous as the corresponding adjustment in the base station of higher level's synchronization base station using it Grade.

With reference to first aspect the first to the 4th kind of any possible implementation, in the 5th kind of possible implementation In, it is described to determine at least one second higher level synchronization base station if the second higher level synchronization base station is used for the alternative of Timing Synchronization Before, including：

Set and safeguard alternative higher level's synchronization station list, the alternative higher level in alternative higher level's synchronization station list is same It is all identical and all identical with the synchronization level of the first higher level synchronization base station to walk the synchronization level of base station, or it is described it is alternative on Alternative higher level's synchronization base station synchronization grade in the synchronous station list of level is different；

It is described to determine that at least one second higher level synchronization base station is：

Based on the determination mode of the second higher level synchronization base station, determine in alternative higher level's synchronization station list extremely Few alternative higher level's synchronization base station is second higher level's synchronization base station.

In the 6th kind of possible implementation of first aspect, if the second higher level synchronization base station is used for timing together Step, the first higher level synchronization base station and second higher level's synchronization base station are determined based on following manner：

Determining at least two has one group of base station of identical synchronization level same for first higher level's synchronization base station and the second higher level Base station is walked, and mutual error is in the range of preset threshold value.

With reference to the 6th kind of possible implementation of first aspect, in the 7th kind of possible implementation, if described Two higher level's synchronization base stations are used for Timing Synchronization, and first higher level's synchronization base station and second higher level's synchronization base station are also true based on following manner It is fixed：

If it is determined that having multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value When, it is first higher level's synchronization base station and second higher level's synchronization base station to determine at least two that group of base stations of synchronization level highest；

Or if it is determined that there is multigroup base station with identical synchronization level and mutual error is in preset threshold value scope When interior, determine that group of maximum base station of at least two signal intensities is first higher level's synchronization base station and second higher level's synchronization base station；

Or if it is determined that there is multigroup base station with identical synchronization level and mutual error is in preset threshold value scope When interior, determine that at least two have that group of base station of identical higher level's synchronization base station same for first higher level's synchronization base station and the second higher level Walk base station.

With reference to the 7th kind of possible implementation of first aspect, in the 8th kind of possible implementation, the determination That group of maximum base station of at least two signal intensities is first higher level's synchronization base station and second higher level's synchronization base station, including：

If it is determined that have multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value, And when having multigroup synchronization level highest base station, determine that group of maximum base station of at least two signal intensities is synchronous for the first higher level Base station and second higher level's synchronization base station；

It is described to determine at least two to have that group of base stations of identical higher level's synchronization base station be first higher level's synchronization base station and the Two higher level's synchronization base stations, including：

If it is determined that have multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value, And when having multigroup synchronization level highest base station, it is first to determine at least two that group of base stations with identical higher level's synchronization base station Higher level's synchronization base station and second higher level's synchronization base station；Or

If it is determined that have multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value, And when having the maximum base station of multigroup signal intensity in multigroup synchronization level highest base station, determine that at least two have and are mutually same as above That group of base station of the synchronous base station of level is first higher level's synchronization base station and second higher level's synchronization base station.

With reference to the 8th kind of possible implementation of first aspect, in the 9th kind of possible implementation, if described Two higher level's synchronization base stations are used for Timing Synchronization, and methods described also includes：

Obtain the position that the second higher level synchronization base station sends synchronizing signal；

Multimedia broadcasting SFN MBSFN sub-frame is arranged on itself relevant position.

With reference to the 8th kind of possible implementation of first aspect, in the tenth kind of possible implementation, if described Two higher level's synchronization base stations are used for Timing Synchronization, and methods described also includes：

Obtain the position that the second higher level synchronization base station receives the synchronizing signal of its higher level's synchronization base station transmission；

MBSFN sub-frame is arranged on itself relevant position.

It is described to be carried out using the second higher level synchronization base station in a kind of the tenth possible implementation of first aspect Timing Synchronization, include before：

When base station link synchronous with first higher level fails, judge that the first higher level synchronization base station is not used to Timing Synchronization；Or

When the first higher level synchronization base station base station link failure synchronous with its higher level, judge that first higher level is same Step base station is not used to Timing Synchronization.

In the 12nd kind of possible implementation of first aspect, the Timing Synchronization is including initial timing synchronization and together Step tracking.

Second aspect of the present invention provides a kind of small base station, including：

Determining module, for determining first higher level's synchronization base station for Timing Synchronization；

The determining module, it is additionally operable to determine at least one second higher level synchronization base station；

Processing module, if being used for the alternative of Timing Synchronization for the second higher level synchronization base station, on described first When the synchronous base station of level is not used to Timing Synchronization, synchronization is timed using the second higher level synchronization base station；

The processing module, if being additionally operable to the second higher level synchronization base station is also used for Timing Synchronization, utilize described One higher level's synchronization base station and/or the second higher level synchronization base station are timed synchronization.

In the first possible implementation of second aspect, if the second higher level synchronization base station is used for Timing Synchronization It is alternative, the determining module is specifically based on following manner and determines the second higher level synchronization base station：It is determined that with described first It is second higher level's synchronization base station that the synchronous base station of level, which has the base station of identical synchronization level,；Or determine that synchronization level highest base station is Second higher level's synchronization base station；Or determine that the maximum base station of signal intensity is second higher level's synchronization base station.

With reference to the first possible implementation of second aspect, in second of possible implementation, the determination Module, it is specially if it is determined that not with described first for determining synchronization level highest base station as second higher level's synchronization base station When higher level's synchronization base station has the base station of identical synchronization level, it is second higher level's synchronization base to determine synchronization level highest base station Stand；

The determining module, be specially for determining the maximum base station of signal intensity as second higher level's synchronization base station if it is determined that Going out base station not synchronous with first higher level has the base station of identical synchronization level or has multiple synchronous with first higher level When base station has the base station of identical synchronization level, determine that the maximum base station of signal intensity is second higher level's synchronization base station；If or really Making base station not synchronous with first higher level has the base station of identical synchronization level and has multiple synchronization level highest bases When standing, determine that the maximum base station of signal intensity is second higher level's synchronization base station.

With reference to the first possible implementation of second aspect, in the third possible implementation, if described Two higher level's synchronization base stations are used for the alternative of Timing Synchronization, and the determining module is additionally operable to：

In the 4th kind of possible implementation of second aspect, if the second higher level synchronization base station is used for Timing Synchronization It is alternative, the small base station also includes：

Adjusting module, if having what is differed for the first higher level synchronization base station base station synchronous with second higher level Synchronization level, and when the second higher level synchronization upgrading base station is the higher level synchronization base station for being currently used in Timing Synchronization, adjustment from Body synchronization level one-level lower than the synchronization level of the second higher level synchronization base station；

Control module, for controlling the base station using the small base station as higher level's synchronization base station correspondingly to adjust synchronization level.

With reference to second aspect the first to the 4th kind of any possible implementation, in the 5th kind of possible implementation In, if the second higher level synchronization base station is used for the alternative of Timing Synchronization, the small base station also includes：

Setup module, for setting and safeguarding alternative higher level's synchronization station list, alternative higher level's synchronization station list In alternative higher level's synchronization base station synchronization grade it is all identical and all identical with the synchronization level of the first higher level synchronization base station, Or alternative higher level's synchronization base station synchronization grade in alternative higher level's synchronization station list is different；

The determining module, for determining that at least one second higher level synchronization base station is specially same based on second higher level The determination mode of base station is walked, determines at least one alternative higher level's synchronization base station in alternative higher level's synchronization station list for the Two higher level's synchronization base stations.

In the 6th kind of possible implementation of second aspect, if the second higher level synchronization base station is used for Timing Synchronization, The determining module determines the first higher level synchronization base station and second higher level's synchronization base station based on following manner：It is determined that at least two Individual one group of base station with identical synchronization level is the first higher level synchronization base station and second higher level's synchronization base station, and mutually it Between error in the range of preset threshold value.

With reference to the 6th kind of possible implementation of second aspect, in the 7th kind of possible implementation, if described Two higher level's synchronization base stations are used for Timing Synchronization, and the determining module also determines the first higher level synchronization base station based on following manner With second higher level's synchronization base station：If it is determined that having multigroup base station with identical synchronization level and mutual error is preset When in threshold range, determine that at least two that group of base stations of synchronization level highest are same for first higher level's synchronization base station and the second higher level Walk base station；Or if it is determined that there is multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value When, determine that group of maximum base station of at least two signal intensities is first higher level's synchronization base station and second higher level's synchronization base station；Or If it is determined that there is multigroup base station with identical synchronization level and when mutual error is in the range of preset threshold value, it is determined that extremely Few two that group of base stations with identical higher level's synchronization base station are first higher level's synchronization base station and second higher level's synchronization base station.

With reference to the 7th kind of possible implementation of second aspect, in the 8th kind of possible implementation, the determination Module, for determining that group of maximum base station of at least two signal intensities is first higher level's synchronization base station and second higher level's synchronization base Stand be specially if it is determined that have multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value, And when having multigroup synchronization level highest base station, determine that group of maximum base station of at least two signal intensities is synchronous for the first higher level Base station and second higher level's synchronization base station；

The determining module, for determining that at least two that group of base stations with identical higher level's synchronization base station are the first higher level Synchronous base station and second higher level's synchronization base station are specially if it is determined that having multigroup base station with identical synchronization level and mutually it Between error in the range of preset threshold value, and when having multigroup synchronization level highest base station, determine that at least two have and are mutually same as above That group of base station of the synchronous base station of level is first higher level's synchronization base station and second higher level's synchronization base station；

Or if it is determined that there is multigroup base station with identical synchronization level and mutual error is in preset threshold value scope It is interior, and when having in multigroup synchronization level highest base station the maximum base station of multigroup signal intensity, determine that at least two have phase That group of base station with higher level's synchronization base station is first higher level's synchronization base station and second higher level's synchronization base station.

With reference to the 8th kind of possible implementation of second aspect, in the 9th kind of possible implementation, if described Two higher level's synchronization base stations are used for Timing Synchronization, and the small base station also includes：

Acquisition module, the position of synchronizing signal is sent for obtaining the second higher level synchronization base station；

The setup module, for being arranged to multimedia broadcasting SFN MBSFN on the small base station relevant position Frame.

With reference to the 8th kind of possible implementation of second aspect, in the tenth kind of possible implementation, if described Two higher level's synchronization base stations are used for Timing Synchronization, and the small base station also includes：

Acquisition module, the synchronizing signal of its higher level's synchronization base station transmission is received for obtaining the second higher level synchronization base station Position；

The setup module, for being arranged to MBSFN sub-frame on the small base station relevant position.

In a kind of the tenth possible implementation of second aspect, the small base station also includes：

Judge module, for when base station link synchronous with first higher level fails, judging that first higher level is same Step base station is not used to Timing Synchronization；Or when the first higher level synchronization base station base station link failure synchronous with its higher level, Judge that the first higher level synchronization base station is not used to Timing Synchronization.

As can be seen from the above technical solutions, a kind of time synchronization method provided in an embodiment of the present invention and small base station, Not only determination is currently used in first higher level's synchronization base station of Timing Synchronization, further defines second higher level's synchronization base station, and it is fixed to be also used for When it is synchronous or for the alternative of Timing Synchronization, it is necessary to again during avoiding current higher level's synchronization base station from being not used to Timing Synchronization The problem of synchronizing source search.

Brief description of the drawings

In order to illustrate the technical solution of the embodiments of the present invention more clearly, used required for being described below to embodiment Accompanying drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present invention, for ability For the those of ordinary skill of domain, on the premise of not paying creative work, it can also be obtained according to these accompanying drawings other attached Figure.

Fig. 1 is a kind of schematic flow sheet of time synchronization method provided in an embodiment of the present invention；

Fig. 2 is another schematic flow sheet of time synchronization method provided in an embodiment of the present invention；

Fig. 3 is another schematic flow sheet of time synchronization method provided in an embodiment of the present invention；

Fig. 4 is another schematic flow sheet of time synchronization method provided in an embodiment of the present invention；

Fig. 5 is the structural representation of small base station provided in an embodiment of the present invention；

Fig. 6 is another structural representation of small base station provided in an embodiment of the present invention；

Fig. 7 is another structural representation of small base station provided in an embodiment of the present invention.

Embodiment

The embodiments of the invention provide a kind of time synchronization method and small base station, for avoid when higher level's synchronization base station without When method is used for Timing Synchronization, small base station needs to re-start the problem of synchronisation source is searched for.

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation describes, it is clear that described embodiment is only part of the embodiment of the present invention, rather than whole embodiments.It is based on Embodiment in the present invention, those of ordinary skill in the art are obtained all other under the premise of creative work is not made Embodiment, belong to the scope of protection of the invention.

It is described in detail individually below.

Fig. 1 is refer to, Fig. 1 is a kind of schematic flow sheet of time synchronization method provided in an embodiment of the present invention, wherein, institute The method of stating includes：

S101, determine first higher level's synchronization base station for Timing Synchronization；

Wherein, the inventive method executive agent is the small base station for needing Timing Synchronization, as micro-base station pico eNB, family are small Base station femto eNB, Home eNodeB HeNB etc., for convenience of describing and understanding, it may be simply referred to as target BS；The Timing Synchronization side Method goes for long-term advancing time division duplex LTE TDD systems and Long Term Evolution FDD LTE FDD systems；

S102, determine at least one second higher level synchronization base station；

It is understood that the first higher level synchronization base station and the phase that second higher level's synchronization base station is the target BS Adjacent base station, wherein, first higher level's synchronization base station is the base station that target BS is currently used in Timing Synchronization；It is another it is contemplated that The first higher level synchronization base station and second higher level's synchronization base station can be small base station, such as pico, femto, HeNB, can also It is other kinds of base station, such as global system for mobile communications (GSM, Global System of Mobile ) or base station (BS, Base in CDMA (CDMA, Code Division Multiple Access) communication Station, BTS, Base Transceiver Station) or WCDMA (WCDMA, Wideband Code Division Multiple Access) in base station (NodeB), can also be the evolved base in LTE and LTE-A Stood (eNB or e-NodeB, evolutional Node B), and the present invention is not especially limited to this.

It can judge that first higher level's synchronization base station and the second higher level are synchronous according to concrete application scene in the embodiment of the present invention The determination order of base station, in some embodiments, can first determine first higher level's synchronization base station, then determine the second higher level synchronization Base station, in some embodiments, first higher level's synchronization base station and second higher level's synchronization base station can be determined simultaneously, is not made herein It is specific to limit.

If S103a, the second higher level synchronization base station are used for the alternative of Timing Synchronization, when the first higher level synchronization base When station is not used to Timing Synchronization, synchronization is timed using the second higher level synchronization base station；

Under preferably, the first higher level synchronization base station is the base station that target BS is currently used in Timing Synchronization, The second higher level synchronization base station is for the alternative of Timing Synchronization when first higher level's synchronization base station is not used to Timing Synchronization Base station；

If S103b, the second higher level synchronization base station are also used for Timing Synchronization, the first higher level synchronization base station is utilized And/or the second higher level synchronization base station is timed synchronization.

Under preferably, the first higher level synchronization base station and second higher level's synchronization base station are all that target BS is current For the base station of Timing Synchronization, the first higher level synchronization base station and second higher level's synchronization base station can carry for target BS simultaneously For Timing Synchronization, can also timesharing provide Timing Synchronization for target BS, it is another it is contemplated that when first higher level is synchronous When a base station in base station and second higher level's synchronization base station is not used to Timing Synchronization, target BS can using others Base station for Timing Synchronization is timed synchronization.

From the foregoing, a kind of time synchronization method provided in an embodiment of the present invention, not only determines to be currently used in timing together First higher level's synchronization base station of step, further defines second higher level's synchronization base station, is also used for Timing Synchronization or for Timing Synchronization Alternatively, so that when avoiding current higher level's synchronization base station from being not used to Timing Synchronization, small base station needs to re-start synchronisation source search Problem.

For convenience of understanding and describing, following examples are used for the alternative of Timing Synchronization for second higher level's synchronization base station respectively It is used to Timing Synchronization both of these case with second higher level's synchronization base station carry out time synchronization method provided in an embodiment of the present invention Concrete analysis：

If assuming in the embodiment of the invention, the second higher level synchronization base station is used for the alternative of Timing Synchronization, i.e., Target BS is when synchronisation source is searched for, it is thus necessary to determine that first higher level's synchronization base station for being currently used in Timing Synchronization and really Fixed at least one second alternative higher level's synchronization base station for Timing Synchronization；Fig. 2 is referred to, Fig. 2 carries for the embodiment of the present invention Another schematic flow sheet of the time synchronization method of confession, wherein, methods described includes：

S201, determine first higher level's synchronization base station for Timing Synchronization；

It is second higher level's synchronization base that S202, determination base station synchronous with first higher level, which have the base station of identical synchronization level, Stand；Or determine that synchronization level highest base station is second higher level's synchronization base station；Or determine that the maximum base station of signal intensity is second Higher level's synchronization base station.

It is understood that signal intensity can be synchronizing signal intensity, reference signal strength, control in the embodiment of the present invention The signal intensity superposition of the combination of signal intensity processed, data signal strength or these signals, is not especially limited herein.

Optionally, in this embodiment, the second higher level synchronization base station can be determined based on S202 mode, It can also be determined based in the following manner：

Further, the determination synchronization level highest base station is that second higher level's synchronization base station can include：

The base station for determining that signal intensity is maximum can include for second higher level's synchronization base station：

If it is determined that base station not synchronous with first higher level has the base station of identical synchronization level or has multiple and institute When stating first higher level's synchronization base station has the base station of identical synchronization level, determine that the maximum base station of signal intensity is same for the second higher level Walk base station；Or, however, it is determined that going out base station not synchronous with first higher level has the base station of identical synchronization level and has multiple During synchronization level highest base station, determine that the maximum base station of signal intensity is second higher level's synchronization base station.

It is understood that prioritizing selection base station synchronous with first higher level has the base station of identical synchronization level, this For sample when first higher level's synchronization base station is not used to Timing Synchronization, target BS can be directly synchronous using the second alternative higher level Base station is timed synchronization, and need not adjust the synchronization level of target BS in itself when being timed synchronization, it is not required that adjusts The synchronization level of whole those base stations using target BS as higher level's synchronization base station；

In some embodiments, target BS directly can determine second higher level's synchronization base according to the height of synchronization level Stand；Further it can also determine that base station not synchronous with first higher level has the base station of identical synchronization level In the case of, it is second higher level's synchronization base station to preferably select synchronization level highest base station；Separately it is understood that synchronization level Highest base station can be understood as the base station that hop count is minimum or node hop count is minimum, and such base station can ensure synchronous essence It is minimum to spend error accumulation；

In some embodiments, target BS directly can determine second higher level's synchronization base according to the strong and weak of signal intensity Stand；Further it can also determine that base station not synchronous with first higher level has the base station of identical synchronization level Or when there are multiple base stations synchronous with first higher level that there is the base station of identical synchronization level, determine the maximum base station of signal intensity For second higher level's synchronization base station；Or if it is determined that base station not synchronous with first higher level has the base station of identical synchronization level And in the case of there are multiple synchronization level highest base stations, determine that the maximum base station of signal intensity is second higher level's synchronization base station.

S203, when the first higher level synchronization base station is not used to Timing Synchronization, utilize the second higher level synchronization base Station is timed synchronization；

Alternatively, if target BS it is determined that one be used for Timing Synchronization first higher level's synchronization base station, and determine one Behind second alternative higher level's synchronization base station of Timing Synchronization, alternative higher level's synchronization base station (i.e. second higher level's synchronization base station) can To be used based in the following manner：

Under an application scenarios, if synchronization of the synchronization level base station synchronous with the first higher level of second higher level's synchronization base station etc. Level is identical, then when first higher level's synchronization base station is not used to Timing Synchronization, alternative second higher level's synchronization upgrading base station For current higher level's synchronization base station, so that target BS can quickly obtain new higher level's synchronization base station.Because new higher level is same Walk the same of the synchronization level base station synchronous with former higher level (i.e. first higher level's synchronization base station) of base station (i.e. second higher level's synchronization base station) It is identical to walk grade, thus the change of higher level's synchronization base station will not cause the synchronization level of target BS to change, target BS New higher level's synchronization base station (i.e. second higher level's synchronization base station) can be directly used to be timed synchronous without adjusting itself Synchronization level, it is not required that synchronization level of the adjustment using target BS as those base stations of higher level's synchronization base station.

Under another application scene, if the first higher level synchronization base station base station synchronous with second higher level has not phase With synchronization level, and when the second higher level synchronization upgrading base station is the higher level synchronization base station for being currently used in Timing Synchronization, mesh Mark base station adjusts its own synchronization level one-level lower than the synchronization level of the second higher level synchronization base station, and controls using it to be upper The base station of the synchronous base station of level correspondingly adjusts synchronization level.

I.e. under the application scenarios, when former higher level's synchronization base station (i.e. first higher level's synchronization base station) is not used to Timing Synchronization When, alternative second higher level's synchronization base station equally upgrades to current higher level's synchronization base station, and target BS can be obtained quickly One new higher level's synchronization base station.But in the synchronization level due to new higher level's synchronization base station (i.e. second higher level's synchronization base station) and original The synchronization level of the synchronous base station (i.e. first higher level's synchronization base station) of level differs, thus the change of higher level's synchronization base station will cause mesh The grade of mark base station changes, and now, target BS can directly use new higher level's synchronization base station (i.e. second higher level's synchronization base Stand) synchronization is timed, but need to adjust the synchronization level of itself one-level lower than the synchronization level of new higher level's synchronization base station, and that The base station using target BS as higher level's synchronization base station is also required to corresponding adjustment synchronization level a bit.

It is understood that in the embodiment, the use of alternative higher level's synchronization base station (i.e. second higher level's synchronization base station) Go for the scene of multiple second higher level synchronization base stations, the present embodiment only with second higher level's synchronization base station alternately Higher level's synchronization base station exemplified by illustrate, do not form limitation of the invention.

Optionally, in the alternative embodiment that the second higher level synchronization base station is used for Timing Synchronization, the timing Synchronous method also includes：

It is understood that the target BS described in the of the invention embodiment maintain all the time it is at least one it is alternative on The synchronous base station (i.e. second higher level's synchronization base station) of level.When alternative higher level's synchronization base station is not used to Timing Synchronization or upgrades to current During higher level synchronization base station for Timing Synchronization, again according to new standby of the selection rule selection one of alternative higher level's synchronization base station Choose level synchronization base station.

In the present embodiment, optionally, target BS is timed synchronization using the second higher level synchronization base station (S203) can also include before：When base station link synchronous with first higher level fails, judge that first higher level is same Step base station is not used to Timing Synchronization；Or when the first higher level synchronization base station base station link failure synchronous with its higher level, Judge that the first higher level synchronization base station is not used to Timing Synchronization.

It is understood that target BS base station link failure synchronous with first higher level, such as detect continuous n times Detect step-out, it may be determined that target BS base station synchronous with first higher level does not have in synchronization, and the N is preset value；Its In, target BS synchronous with first higher level base station link failure link failure can be due to first higher level's synchronization base station with Office closes, or caused by the reason such as bad channel quality between target BS base station synchronous with the first higher level；On described first The synchronous base station of level base station link synchronous with its higher level fails, can be due to first higher level's synchronization base station higher level's synchronization base station with Office closes, or bad channel quality between higher level's synchronization base station of first higher level's synchronization base station base station synchronous with the first higher level etc. Caused by reason, the present invention is not especially limited to this.

In addition, in embodiment of the present invention, the Timing Synchronization can include initial timing synchronization and synchronized tracking, its In, initial timing synchronization refers to obtain timing for the first time when target BS or target terminal network, and now needs primary/secondary by scanning Synchronizing signal (PSS/SSS, Primary/Secondary Synchronization Signal) obtains；Synchronized tracking refers to Maintenance is synchronous on the basis of having obtained timing, by detecting public reference signal (CRS, Common Reference Signal) fine setting of timing is realized to remain synchronous.

From the foregoing, a kind of time synchronization method provided in an embodiment of the present invention, not only determines to be currently used in timing together First higher level's synchronization base station of step, further defines second higher level's synchronization base station, for the alternative of Timing Synchronization, to avoid on current When the synchronous base station of level is not used to Timing Synchronization, small base station needs to re-start the problem of synchronisation source is searched for, so as to use Second higher level's synchronization base station continues to keep synchronous, reduce base station and base station, user equipment (UE, User Equipment) and UE it Between interference.

If assuming in the embodiment of the invention, the second higher level synchronization base station is used for the alternative of Timing Synchronization, with Unlike a upper embodiment, in the embodiment, before at least one second higher level synchronization base station of determination, in addition to Set and safeguard alternative higher level's synchronization station list；I.e. target BS is when synchronisation source is searched for, it is thus necessary to determine that one current First higher level's synchronization base station for Timing Synchronization, it is also necessary to safeguard alternative higher level's synchronization station list, be readily apparent that It is that alternative higher level's synchronization station list includes several alternative higher level's synchronization base stations；Fig. 3 is referred to, Fig. 3 is real for the present invention Another schematic flow sheet of the time synchronization method of example offer is provided, wherein, methods described includes：

S301, determine first higher level's synchronization base station for Timing Synchronization；

S302, setting simultaneously safeguard alternative higher level's synchronization station list；

Wherein, alternative higher level's synchronization base station synchronization grade in alternative higher level's synchronization station list is all identical, and all It is identical with the synchronization level of the first higher level synchronization base station, or, on alternative in alternative higher level's synchronization station list The synchronous base station synchronization grade of level is different；

S303, determine that at least one alternative higher level's synchronization base station in alternative higher level's synchronization station list is on second The synchronous base station of level；

It is understood that under preferably, second higher level's synchronization base station described in a upper embodiment can be based on Determination mode, determine that at least one alternative higher level's synchronization base station in alternative higher level's synchronization station list is the second higher level Synchronous base station；The mode that second higher level's synchronization base station is determined in the embodiment is：It is determined that base synchronous with first higher level The base station with identical synchronization level of standing is second higher level's synchronization base station；Or determine that synchronization level highest base station is the second higher level Synchronous base station；Or determine that the maximum base station of signal intensity is second higher level's synchronization base station.

It is understood that in this embodiment, on alternative in either described alternative higher level's synchronization station list Alternative higher level's synchronization base in the synchronous base station synchronization grade of level all identical scenes, or alternative higher level's synchronization station list The different scene of synchronization level of standing, at least one alternative higher level of selection determination is synchronous in alternative higher level's synchronization station list When base station is the second higher level synchronization base station, can prioritizing selection base station synchronous with first higher level there is identical synchronization level Base station, so when first higher level's synchronization base station is not used to Timing Synchronization, target BS can be directly using alternative the Two higher level's synchronization base stations are timed synchronization, and need not adjust the synchronization level of target BS in itself when being timed synchronization, Also without synchronization level of the adjustment using target BS as those base stations of higher level's synchronization base station；

S304, when the first higher level synchronization base station is not used to Timing Synchronization, utilize the second higher level synchronization base Station is timed synchronization；

Alternatively, if target BS is it is determined that a first higher level's synchronization base station for being used for Timing Synchronization, and from alternative After second alternative higher level's synchronization base station for Timing Synchronization is determined in the synchronous station list of level, second higher level's synchronization base Standing can be used based in the following manner：

Under an application scenarios, when first higher level's synchronization base station is not used to Timing Synchronization, second higher level's synchronization base station Upgrade to current higher level's synchronization base station, so that target BS can quickly obtain new higher level's synchronization base station.If on second The synchronization level of the synchronous base station of level is identical with the synchronization level of first higher level's synchronization base station, and the change of higher level's synchronization base station will not draw The synchronization level for playing target BS changes, and target BS can directly using new higher level's synchronization base station, (i.e. the second higher level be same Step base station) it is timed synchronously without adjusting the synchronization level of itself, it is not required that adjustment is same by higher level of target BS Walk the synchronization level of those base stations of base station.

Under another application scene, if the first higher level synchronization base station base station synchronous with the second higher level has what is differed Synchronization level, and when the second higher level synchronization upgrading base station is the higher level synchronization base station for being currently used in Timing Synchronization, target base Stand and adjust its own synchronization level one-level lower than the synchronization level of the second higher level synchronization base station, and control same using it as higher level The base station of step base station correspondingly adjusts synchronization level.

It should be noted that in the embodiment of the invention, only with the determination side based on above-mentioned second higher level synchronization base station Formula, selected from alternative higher level's synchronization station list at least one alternative higher level's synchronization base station as second higher level's synchronization base station for Example is embodied the determination of second higher level's synchronization base station, but does not form limitation of the invention, in some embodiments In, alternative higher level's synchronization base station in alternative higher level's synchronization station list can be ranked up setting, institute according to certain rule State the determination mode that rule is referred to above-mentioned second higher level synchronization base station, i.e., synchronization level identical with first higher level's synchronization base station Base station come before, behind base station that base station synchronization grade synchronous with the first higher level differs comes；Synchronization level is small i.e. same Before the high base station of step grade comes, synchronization level is behind the low base station of synchronization level comes greatly；By the big base of signal intensity Before station comes, behind the small base station of signal intensity comes.If in this embodiment, alternative higher level's synchronization station list In alternative higher level's synchronization base station by it is described it is regularly arranged it is good after, target BS can determine alternative higher level's synchronization base station row At least one alternative higher level's synchronization base station in table is second higher level's synchronization base station；It can not be used in the first higher level synchronization base station When Timing Synchronization, synchronization is timed using the second higher level synchronization base station.

It is understood that to maintain an alternative higher level all the time same for the target BS described in the of the invention embodiment Walk station list.For the optional mode, if the rule are pressed in alternative higher level's synchronization base station in alternative higher level's synchronization station list Then arrange, when first alternative higher level's synchronization upgrading base station in alternative higher level's synchronization station list is synchronous for current higher level During base station, second alternative higher level's synchronization upgrading base station in alternative higher level's synchronization station list arranges for alternative higher level's synchronization base station First alternative higher level's synchronization base station in table.Separately it is contemplated that in implementation implementation, when alternative higher level's synchronization base station , can be same from alternative higher level by alternative higher level's synchronization base station when alternative higher level's synchronization base station in list is not used to Timing Synchronization Removed in step station list.

In the present embodiment, optionally, target BS is timed synchronization using the second higher level synchronization base station (S304), can also include before：When base station link synchronous with first higher level fails, judge that first higher level is same Step base station is not used to Timing Synchronization；Or when the first higher level synchronization base station base station link failure synchronous with its higher level, Judge that the first higher level synchronization base station is not used to Timing Synchronization.

In addition, in embodiment of the present invention, the Timing Synchronization can include initial timing synchronization and synchronized tracking, its In, initial timing synchronization refers to obtain timing for the first time when target BS or target terminal network, and now needs primary/secondary by scanning Synchronizing signal obtains；Synchronized tracking refers to remain synchronous on the basis of timing has been obtained, by detecting public reference signal To realize the fine setting of timing to remain synchronous.

From the foregoing, a kind of time synchronization method provided in an embodiment of the present invention, not only determines to be currently used in timing together First higher level's synchronization base station of step, further define at least one alternative higher level's synchronization base in alternative higher level's synchronization station list Stand and be used as second higher level's synchronization base station, for the alternative of Timing Synchronization, to avoid current higher level's synchronization base station from being not used to timing When synchronous, small base station needs to re-start the problem of synchronisation source is searched for, so as to continue to protect using second higher level's synchronization base station Synchronization is held, reduces the interference between base station and base station, UE and UE.

If assuming in the embodiment of the invention, the second higher level synchronization base station is also used for Timing Synchronization, i.e. target Base station is when synchronisation source is searched for, it is thus necessary to determine that at least two are currently used in Timing Synchronization higher level's synchronization base station, are one respectively Individual first higher level synchronization base station and at least one second higher level synchronization base station；Fig. 4 is referred to, Fig. 4 provides for the embodiment of the present invention Time synchronization method another schematic flow sheet, wherein, methods described includes：

S401, determine that at least two have one group of base station of identical synchronization level on first higher level's synchronization base station and second The synchronous base station of level, and mutual error is in the range of preset threshold value.

Optionally, in this embodiment, the first higher level synchronization base station and second higher level's synchronization base station can be based on S401 mode is determined, and can also be determined based in the following manner：

Further, however, it is determined that go out to have multigroup base station with identical synchronization level and mutual error is in preset threshold When in the range of value, determine that at least two that group of base stations of synchronization level highest are synchronous for first higher level's synchronization base station and the second higher level Base station；

Further, that group of base station for determining that at least two signal intensities are maximum for first higher level's synchronization base station and Second higher level's synchronization base station, can include：If it is determined that there are multigroup base station with identical synchronization level and mutual mistake Difference is in the range of preset threshold value, and when having multigroup synchronization level highest base station, determines maximum that of at least two signal intensities Group base station is first higher level's synchronization base station and second higher level's synchronization base station；

It is described to determine at least two to have that group of base stations of identical higher level's synchronization base station be first higher level's synchronization base station and the Two higher level's synchronization base stations, can include：If it is determined that there are multigroup base station with identical synchronization level and mutual error In the range of preset threshold value, and when having multigroup synchronization level highest base station, determine that at least two have identical higher level's synchronization base That group of base station stood is first higher level's synchronization base station and second higher level's synchronization base station；Or if it is determined that having multigroup has identical synchronization The base station of grade and mutual error is in the range of preset threshold value, and have in multigroup synchronization level highest base station multigroup During the base station of signal intensity maximum, determine that at least two have that group of base stations of identical higher level's synchronization base station synchronous for the first higher level Base station and second higher level's synchronization base station.

It is understood that in the embodiment of the present invention, at least two are used for higher level's synchronization base station of Timing Synchronization, and it is selected It is determined that may be referred to the implementation process for being used for alternative higher level's synchronization base station in above-described embodiment, that is, meeting to determine at least two Under conditions of the individual base station with identical synchronization level and mutual error are in the range of the preset threshold value, prioritizing selection is synchronous That group of high base station of grade, that group of big base station of next prioritizing selection signal intensity.In this embodiment, if there is multigroup base station In the base station identical and suitable signal intensity in synchronization level, prioritizing selection possesses the base station of identical higher level's synchronization base station.

S402, when the first higher level synchronization base station is not used to Timing Synchronization, utilize the second higher level synchronization base Station is timed synchronization；

Alternatively, if target BS determines a first higher level's synchronization base station for being used for Timing Synchronization, and one is determined For second higher level's synchronization base station of Timing Synchronization, i.e. target BS determines two higher level's synchronization base stations, then the two higher levels are same Step base station (i.e. first higher level's synchronization base station and second higher level's synchronization base station) can be used based in the following manner：

Target BS is timed synchronization to two higher level's synchronization base stations simultaneously, receives the synchronization of two higher level's synchronization base stations Signal, now, methods described can also include：Obtain the position that the second higher level synchronization base station sends synchronizing signal；Certainly Multimedia broadcasting SFN (MBSFN, Multimedia Broadcast Single are arranged on body relevant position Frequency Network) subframe, the purpose is to realize the synchronization of target BS；Under the embodiment, methods described can be with Including：Obtain the position that the second higher level synchronization base station receives the synchronizing signal of its higher level's synchronization base station transmission；In itself phase Answer and MBSFN sub-frame is arranged on position, the purpose is to avoid the interference to second higher level's synchronization base station；That is target BS MBSFN sub-frame be union that two higher level's synchronization base stations receive subframe；In MBSFN sub-frame, target BS will not send number According to UE can also know that the subframe receives data for MBSFN sub-frame without going in configuration information before.

It is understood that in the embodiment, two higher level's synchronization base stations are (i.e. on first higher level's synchronization base station and second The synchronous base station of level) use go for the scenes of multiple higher level's synchronization base stations, the present embodiment is only with higher level's synchronization base Stand and second higher level's synchronization base station exemplified by current higher level's synchronization base station as illustrating, do not form the limit to the present invention It is fixed.

It should be noted that to maintain at least two higher levels all the time same for the target BS described in the of the invention embodiment Walk base station, i.e. first higher level's synchronization base station and at least one second higher level synchronization base station.When at least two higher level's synchronization base stations Higher level's synchronization base station when being not used to Timing Synchronization, the base station is not re-used as higher level's synchronization base station.When target BS When higher level's synchronization base station is less than two, according to one base station of selection rule increase of higher level's synchronization base station, the base station newly increased should Meet that identical with existing higher level's synchronization base station synchronization grade and synchronous error is in the range of the preset threshold value.

Optionally, target BS is timed synchronization (S402) using the second higher level synchronization base station, before can be with Including：When base station link synchronous with first higher level fails, it is fixed to judge that the first higher level synchronization base station is not used to When it is synchronous；Or when the first higher level synchronization base station base station link failure synchronous with its higher level, judge on described first The synchronous base station of level is not used to Timing Synchronization.

From the foregoing, a kind of time synchronization method provided in an embodiment of the present invention, not only determines to be currently used in timing together First higher level's synchronization base station of step, further defines second higher level's synchronization base station, is also used for Timing Synchronization, to avoid the first higher level same When step base station is not used to Timing Synchronization, small base station needs to re-start the problem of synchronisation source is searched for, so as to use second Higher level's synchronization base station continues to keep synchronous, reduces the interference between base station and base station, UE and UE.

For ease of preferably implementing the technical scheme of the embodiment of the present invention, the embodiment of the present invention also provides above-mentioned for implementing The relevant apparatus of time synchronization method.Wherein the implication of noun is identical with the method for above-mentioned Timing Synchronization, implements details It may be referred to the explanation in embodiment of the method.

Fig. 5 is refer to, Fig. 5 is a kind of structural representation of small base station 500 provided in an embodiment of the present invention, wherein, it is described Small base station 500 can be applied to LTE TDD systems and LTE FDD systems, the small base station 500 can be micro-base station pico eNB, Small base station femto eNB of family, Home eNodeB HeNB etc., the small base station 500 include：

Determining module 501, for determining first higher level's synchronization base station for Timing Synchronization；

The determining module 501, it is additionally operable to determine at least one second higher level synchronization base station；

Processing module 502, if being used for the alternative of Timing Synchronization for the second higher level synchronization base station, when described first When higher level's synchronization base station is not used to Timing Synchronization, synchronization is timed using the second higher level synchronization base station；

Under preferably, the first higher level synchronization base station is current for the synchronous small base station (i.e. target BS) of needs For the base station of Timing Synchronization, the second higher level synchronization base station is when first higher level's synchronization base station is not used to Timing Synchronization Candidate BS for Timing Synchronization；

The processing module 502, if being additionally operable to the second higher level synchronization base station is also used for Timing Synchronization, described in First higher level's synchronization base station and/or the second higher level synchronization base station are timed synchronization.

From the foregoing, a kind of small base station 500 provided in an embodiment of the present invention, not only determines to be currently used in Timing Synchronization First higher level's synchronization base station, second higher level's synchronization base station is further defined, is also used for Timing Synchronization or for the alternative of Timing Synchronization, During avoiding current higher level's synchronization base station from being not used to Timing Synchronization, small base station needs to re-start the problem of synchronisation source is searched for, So as to continue to keep synchronous using alternative or other base stations for being used for Timing Synchronization, base station and base station, UE and UE are reduced Between interference.

For convenience of understanding and describing, following examples are used for the alternative of Timing Synchronization for second higher level's synchronization base station respectively Small base station provided in an embodiment of the present invention is specifically divided for Timing Synchronization both of these case with second higher level's synchronization base station Analysis：

If assuming in the embodiment of the invention, the second higher level synchronization base station is used for the alternative of Timing Synchronization, i.e., Target BS is when synchronisation source is searched for, it is thus necessary to determine that first higher level's synchronization base station for being currently used in Timing Synchronization and really Fixed at least one second alternative higher level's synchronization base station for Timing Synchronization；

Optionally, the determining module 501 is specifically based on following manner and determines the second higher level synchronization base station：It is determined that with It is second higher level's synchronization base station that the first higher level synchronization base station, which has the base station of identical synchronization level,；Or determine synchronization level most High base station is second higher level's synchronization base station；Or determine that the maximum base station of signal intensity is second higher level's synchronization base station.

Further, the determining module 501, for determining that synchronization level highest base station is second higher level's synchronization base station Specially if it is determined that when base station not synchronous with first higher level has the base station of identical synchronization level, synchronization level is determined Highest base station is second higher level's synchronization base station；

The determining module 501, if for determining the maximum base station of signal intensity for second higher level's synchronization base station specially Determine that base station not synchronous with first higher level has the base station of identical synchronization level or has multiple and first higher level When synchronous base station has the base station of identical synchronization level, determine that the maximum base station of signal intensity is second higher level's synchronization base station；Or Person, however, it is determined that going out base station not synchronous with first higher level has the base station of identical synchronization level and have multiple synchronization levels most During high base station, determine that the maximum base station of signal intensity is second higher level's synchronization base station.

It is understood that the prioritizing selection of determining module 501 base station synchronous with first higher level have it is identical same The base station of grade is walked, so when first higher level's synchronization base station is not used to Timing Synchronization, target BS can be directly using standby Second higher level's synchronization base station of choosing is timed synchronization, and need not adjust the synchronization of target BS in itself when being timed synchronization Grade, it is not required that synchronization level of the adjustment using target BS as those base stations of higher level's synchronization base station；

In some embodiments, if the second higher level synchronization base station is used for the alternative of Timing Synchronization, target BS exists When searching for synchronisation source, it is thus necessary to determine that a first higher level's synchronization base station for being currently used in Timing Synchronization, it is also necessary to safeguard one Individual alternative higher level's synchronization station list；Fig. 6 is referred to, Fig. 6 is the structural representation of small base station 600 in the embodiment, described Small base station, which is removed, includes determining module 501 and processing module 502, in addition to：Setup module 503, it is alternative for setting and safeguarding The synchronous station list of level；The determining module 501, for determining that at least one second higher level synchronization base station is specially based on described The determination mode of second higher level's synchronization base station, determine that at least one alternative higher level in alternative higher level's synchronization station list is same Step base station is second higher level's synchronization base station.Wherein, alternative higher level's synchronization base station in alternative higher level's synchronization station list is same It is all identical and all identical with the synchronization level of the first higher level synchronization base station to walk grade, or alternative higher level's synchronization base station Alternative higher level's synchronization base station synchronization grade in list is different；

Optionally, if the second higher level synchronization base station is used for the alternative of Timing Synchronization, determined described in the embodiment Module 501 can be also used for：

Alternatively, if the second higher level synchronization base station is used for the alternative of Timing Synchronization, the small base station 600 can also wrap Include：Adjusting module, if there is the synchronization differed for the first higher level synchronization base station base station synchronous with second higher level Grade, and when the second higher level synchronization upgrading base station is the higher level synchronization base station for being currently used in Timing Synchronization, it is same to adjust itself Walk grade one-level lower than the synchronization level of the second higher level synchronization base station；Control module, for control using the small base station as The base station of higher level's synchronization base station correspondingly adjusts synchronization level.

Further alternative, the small base station 600 can also include：Judge module, for when same with first higher level When walking base station link failure, judge that the first higher level synchronization base station is not used to Timing Synchronization；Or on described first When the synchronous base station of level base station link synchronous with its higher level fails, it is same to judge that the first higher level synchronization base station is not used to timing Step.

It is understood that target BS base station link failure synchronous with first higher level, such as detect continuous n times Detect step-out, it may be determined that target BS base station synchronous with first higher level does not have in synchronization, and the N is preset value；Its In, target BS synchronous with first higher level base station link failure link failure can be due to first higher level's synchronization base station with Office closes, or caused by the reason such as bad channel quality between target BS base station synchronous with the first higher level；On described first The synchronous base station of level base station link synchronous with its higher level fails, can be due to first higher level's synchronization base station higher level's synchronization base station with Office closes, or bad channel quality between higher level's synchronization base station of first higher level's synchronization base station base station synchronous with the first higher level etc. Caused by reason, the present invention is not especially limited to this.In addition, in embodiment of the present invention, the Timing Synchronization can include Initial timing synchronization and synchronized tracking.

From the foregoing, a kind of small base station 600 provided in an embodiment of the present invention, not only determines to be currently used in Timing Synchronization First higher level's synchronization base station, second higher level's synchronization base station is further defined, for the alternative of Timing Synchronization, or, it is determined that it is described At least one alternative higher level's synchronization base station is same for timing as second higher level's synchronization base station in alternative higher level's synchronization station list Step it is alternative, during avoiding current higher level's synchronization base station from being not used to Timing Synchronization, small base station, which needs to re-start synchronisation source, to be searched The problem of rope, so as to continue to keep synchronous using second higher level's synchronization base station, reduce between base station and base station, UE and UE Interference.

If assuming in the embodiment of the invention, the second higher level synchronization base station is also used for Timing Synchronization, i.e. target Base station is when synchronisation source is searched for, it is thus necessary to determine that at least two are currently used in Timing Synchronization higher level's synchronization base station, are one respectively Individual first higher level synchronization base station and at least one second higher level synchronization base station；

Under preferably, the determining module 501 can determine the first higher level synchronization base based on following manner Stand and second higher level's synchronization base station：Determining at least two has one group of base station of identical synchronization level synchronous for first higher level Base station and second higher level's synchronization base station, and mutual error is in the range of preset threshold value.

Optionally, the determining module 501 is also determined on the first higher level synchronization base station and second based on following manner The synchronous base station of level：If it is determined that having multigroup base station with identical synchronization level and mutual error is in preset threshold value scope When interior, it is first higher level's synchronization base station and second higher level's synchronization base station to determine at least two that group of base stations of synchronization level highest； Or if it is determined that there is multigroup base station with identical synchronization level and when mutual error is in the range of preset threshold value, it is determined that That group of maximum base station of at least two signal intensities is first higher level's synchronization base station and second higher level's synchronization base station；Or if it is determined that There is multigroup base station with identical synchronization level and when mutual error is in the range of preset threshold value, determine at least two tools That group of base station for having identical higher level's synchronization base station is first higher level's synchronization base station and second higher level's synchronization base station.

Further, the determining module 501, for determining that group of maximum base station of at least two signal intensities for the One higher level's synchronization base station and second higher level's synchronization base station be specially if it is determined that have multigroup base station with identical synchronization level and Mutual error determines at least two signals in the range of preset threshold value, and when having multigroup synchronization level highest base station That group of base station of maximum intensity is first higher level's synchronization base station and second higher level's synchronization base station；The determining module 501, for true Fixed at least two that group of base stations with identical higher level's synchronization base station are first higher level's synchronization base station and second higher level's synchronization base station Specially if it is determined that having multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value, and When having multigroup synchronization level highest base station, it is on first to determine at least two that group of base stations with identical higher level's synchronization base station The synchronous base station of level and second higher level's synchronization base station；Or if it is determined that have multigroup base station with identical synchronization level and between each other Error in the range of preset threshold value, and have in multigroup synchronization level highest base station the maximum base station of multigroup signal intensity When, determine that at least two have that group of base station of identical higher level's synchronization base station synchronous for first higher level's synchronization base station and the second higher level Base station.

Alternatively, if the second higher level synchronization base station is used for Timing Synchronization, the small base station 600 can also include：

The setup module 503, for being arranged to multimedia broadcasting SFN MBSFN on the small base station relevant position Subframe.

The setup module 503, for being arranged to MBSFN sub-frame on the small base station relevant position.

From the foregoing, a kind of small base station 600 provided in an embodiment of the present invention, not only determines to be currently used in Timing Synchronization First higher level's synchronization base station, second higher level's synchronization base station is further defined, is also used for Timing Synchronization, to avoid first higher level's synchronization base When station is not used to Timing Synchronization, small base station needs to re-start the problem of synchronisation source is searched for, so as to use the second higher level Synchronous base station continues to keep synchronous, reduces the interference between base station and base station, UE and UE.

It is apparent to those skilled in the art that for convenience and simplicity of description, the small base of foregoing description Stand and the specific work process of unit module in small base station, may be referred to the correspondence in the embodiment of the method for foregoing Timing Synchronization Process, it will not be repeated here.

It refer to Fig. 7, Fig. 7 is the structural representation of the small base station 700 of another kind provided in an embodiment of the present invention, the small base Stand and 700 can be applied to LTE TDD systems and LTE FDD systems, the small base station 500 can be micro-base station pico eNB, family Small base station femto eNB, Home eNodeB HeNB etc., the small base station 700 include input unit 701, output device 702, processing Device 703, wherein, the processor 703 performs following steps：

It is determined that first higher level's synchronization base station for Timing Synchronization；Determine at least one second higher level synchronization base station；If institute State second higher level's synchronization base station and be used for the alternative of Timing Synchronization, then when the first higher level synchronization base station is not used to Timing Synchronization When, it is timed synchronization using the second higher level synchronization base station；If the second higher level synchronization base station is also used for Timing Synchronization, Then synchronization is timed using the first higher level synchronization base station and/or the second higher level synchronization base station.

In one embodiment, it is preferable that described if the second higher level synchronization base station is used for the alternative of Timing Synchronization Processor 703 can also carry out following steps：

The second higher level synchronization base station is determined based on following manner：It is determined that base station synchronous with first higher level has phase Base station with synchronization level is second higher level's synchronization base station；Or determine that synchronization level highest base station is second higher level's synchronization base Stand；Or determine that the maximum base station of signal intensity is second higher level's synchronization base station.

Preferably, the processor 703 determines that synchronization level highest base station is second higher level's synchronization base station, specific bag Include：

Wherein, the base station for determining that signal intensity is maximum is second higher level's synchronization base station, including：

Preferably, if the second higher level synchronization base station is used for the alternative of Timing Synchronization, the processor 703 can also be held Row following steps：

Preferably, it is described to determine at least one second if the second higher level synchronization base station is used for the alternative of Timing Synchronization Before higher level's synchronization base station, the processor 703 can also carry out following steps：

In another embodiment, it is preferable that if the second higher level synchronization base station is used for Timing Synchronization, the processing Device 703 can also carry out following steps：

The first higher level synchronization base station and second higher level's synchronization base station are determined based on following manner：Determine at least two tools One group of base station for having identical synchronization level is first higher level's synchronization base station and second higher level's synchronization base station, and mutual error In the range of preset threshold value.

Preferably, if the second higher level synchronization base station is used for Timing Synchronization, the processor 703 can also carry out as follows Step：

First higher level's synchronization base station and second higher level's synchronization base station are also determined based on following manner：If it is determined that there is multigroup tool There is the base station of identical synchronization level and when mutual error is in the range of preset threshold value, determine at least two synchronization levels most That group of high base station is first higher level's synchronization base station and second higher level's synchronization base station；

Preferably, if the second higher level synchronization base station is used for Timing Synchronization, the processor 703 determines at least two letters That group of base station of number maximum intensity is first higher level's synchronization base station and second higher level's synchronization base station, is specifically included：

Obtain the position that the second higher level synchronization base station sends synchronizing signal；More matchmakers are arranged on itself relevant position Body broadcast single frequency network MBSFN sub-frame.

Obtain the position that the second higher level synchronization base station receives the synchronizing signal of its higher level's synchronization base station transmission；At itself MBSFN sub-frame is arranged on relevant position.

Preferably, the processor 703 is timed synchronization using the second higher level synchronization base station, can also hold before Row following steps：

When base station link synchronous with first higher level fails, judge that the first higher level synchronization base station is not used to Timing Synchronization；Or when the first higher level synchronization base station base station link failure synchronous with its higher level, judge described first Higher level's synchronization base station is not used to Timing Synchronization.

In embodiments of the present invention, the Timing Synchronization includes initial timing synchronization and synchronized tracking, wherein, initial timing Synchronously refer to obtain timing for the first time when target BS or target terminal network, now need to obtain by scanning primary/secondary synchronizing signal Arrive；Synchronized tracking refers to remain synchronous on the basis of timing has been obtained, realized regularly by detecting public reference signal Fine setting to remain synchronous.

From the foregoing, a kind of small base station provided in an embodiment of the present invention, in some embodiments, is not only determined current For first higher level's synchronization base station of Timing Synchronization, second higher level's synchronization base station is further defined, for the alternative of Timing Synchronization； In some embodiments, not only determine to be currently used in first higher level's synchronization base station of Timing Synchronization, further define it is described it is alternative on At least one alternative higher level's synchronization base station is as second higher level's synchronization base station in the synchronous station list of level, for the standby of Timing Synchronization Choosing；In some embodiments, not only determination is currently used in first higher level's synchronization base station of Timing Synchronization, further defines on second The synchronous base station of level, is also used for Timing Synchronization, and during avoiding first higher level's synchronization base station from being not used to Timing Synchronization, small base station needs The problem of re-starting synchronisation source search, so as to continue to keep synchronous using second higher level's synchronization base station, reduce base station and Interference between base station, UE and UE.

It is apparent to those skilled in the art that for convenience and simplicity of description, the small base of foregoing description The specific work process stood, the corresponding process in the embodiment of the method for foregoing Timing Synchronization is may be referred to, will not be repeated here.

In several embodiments provided herein, it should be understood that disclosed apparatus and method, it can be passed through Its mode is realized.For example, device embodiment described above is only schematical, for example, the division of the unit, only Only a kind of division of logic function, there can be other dividing mode when actually realizing, such as multiple units or component can be tied Another system is closed or is desirably integrated into, or some features can be ignored, or do not perform.It is another, it is shown or discussed Mutual coupling or direct-coupling or communication connection can be the INDIRECT COUPLINGs or logical by some interfaces, device or unit Letter connection, can be electrical, mechanical or other forms.

The unit illustrated as separating component can be or may not be physically separate, show as unit The part shown can be or may not be physical location, you can with positioned at a place, or can also be distributed to multiple On NE.Some or all of unit therein can be selected to realize the mesh of this embodiment scheme according to the actual needs 's.

In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, can also That unit is individually physically present, can also two or more units it is integrated in a unit.Above-mentioned integrated list Member can both be realized in the form of hardware, can also be realized in the form of SFU software functional unit.

If the integrated unit is realized in the form of SFU software functional unit and is used as independent production marketing or use When, it can be stored in a computer read/write memory medium.Based on such understanding, technical scheme is substantially The part to be contributed in other words to prior art or all or part of the technical scheme can be in the form of software products Embody, the computer software product is stored in a storage medium, including some instructions are causing a computer Equipment (can be personal computer, server, or network equipment etc.) performs the complete of each embodiment methods described of the present invention Portion or part steps.And foregoing storage medium includes：USB flash disk, mobile hard disk, read-only storage (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disc or CD etc. are various can store journey The medium of sequence code.

A kind of time synchronization method provided by the present invention and small base station are described in detail above, for ability The those skilled in the art in domain, according to the thought of the embodiment of the present invention, change is had in specific embodiments and applications Part, in summary, this specification content should not be construed as limiting the invention.

Claims

A kind of 1. time synchronization method, it is characterised in that including：

It is determined that first higher level's synchronization base station for Timing Synchronization；

Determine at least one second higher level synchronization base station；

If the second higher level synchronization base station is used for the alternative of Timing Synchronization, when the first higher level synchronization base station is not used to During Timing Synchronization, synchronization is timed using the second higher level synchronization base station；

If the second higher level synchronization base station is also used for Timing Synchronization, the first higher level synchronization base station and/or described is utilized Second higher level's synchronization base station is timed synchronization；

It is described to be timed synchronization using the second higher level synchronization base station, include before：

When base station link synchronous with first higher level fails, judge that the first higher level synchronization base station is not used to timing It is synchronous；Or

When the first higher level synchronization base station base station link failure synchronous with its higher level, the first higher level synchronization base is judged Station is not used to Timing Synchronization；

If the second higher level synchronization base station is used for Timing Synchronization, the first higher level synchronization base station and second higher level's synchronization base station Determined based on following manner：

Determine that at least two one group of base station with identical synchronization level are first higher level's synchronization base station and second higher level's synchronization base Stand, and mutual synchronization timing error is in the range of preset threshold value；The identical synchronization level is referred to as synchronous hop count phase Together.
2. method according to claim 1, it is characterised in that if the second higher level synchronization base station is used for the standby of Timing Synchronization Choosing, the second higher level synchronization base station are determined based on following manner：

It is determined that it is second higher level's synchronization base station that base station synchronous with first higher level, which has the base station of identical synchronization level,；

Or determine that synchronization level highest base station is second higher level's synchronization base station；

Or determine that the maximum base station of signal intensity is second higher level's synchronization base station.
3. method according to claim 2, it is characterised in that the determination synchronization level highest base station is that the second higher level is same Base station is walked, including：

If it is determined that when base station not synchronous with first higher level has the base station of identical synchronization level, determine synchronization level most High base station is second higher level's synchronization base station；

The base station for determining that signal intensity is maximum is second higher level's synchronization base station, including：

If it is determined that base station not synchronous with first higher level has the base station of identical synchronization level or had multiple with described the When one higher level's synchronization base station has the base station of identical synchronization level, determine that the maximum base station of signal intensity is second higher level's synchronization base Stand；Or

If it is determined that base station not synchronous with first higher level has the base station of identical synchronization level and has multiple synchronization levels During highest base station, determine that the maximum base station of signal intensity is second higher level's synchronization base station.
4. method according to claim 2, it is characterised in that if the second higher level synchronization base station is used for the standby of Timing Synchronization Choosing, methods described also include：

Used if the second higher level synchronization base station is not used to Timing Synchronization or the second higher level synchronization upgrading base station to be current When the higher level synchronization base station of Timing Synchronization, the determination mode based on the second higher level synchronization base station determines new alternative higher level Synchronous base station.
5. method according to claim 1, it is characterised in that if the second higher level synchronization base station is used for the standby of Timing Synchronization Choosing, methods described also include：

If the first higher level synchronization base station base station synchronous with second higher level has the synchronization level that differs, and described the When two higher level's synchronization upgrading base stations are the higher level synchronization base station for being currently used in Timing Synchronization, itself synchronization level is adjusted than described The low one-level of synchronization level of two higher level's synchronization base stations, and control synchronous etc. as the corresponding adjustment in the base station of higher level's synchronization base station using it Level.
6. according to any one of claim 2 to 5 methods described, it is characterised in that if the second higher level synchronization base station is used to determine When it is synchronous alternative, it is described determine at least one second higher level synchronization base station before, including：

Set and safeguard alternative higher level's synchronization station list, alternative higher level's synchronization base in alternative higher level's synchronization station list The synchronization level stood is all identical, and all identical with the synchronization level of the first higher level synchronization base station, or the alternative higher level is same The alternative higher level's synchronization base station synchronization grade walked in station list is different；

It is described to determine that at least one second higher level synchronization base station is：

Based on the determination mode of the second higher level synchronization base station, at least one in alternative higher level's synchronization station list is determined Individual alternative higher level's synchronization base station is second higher level's synchronization base station.
7. method according to claim 6, it is characterised in that if the second higher level synchronization base station is used for Timing Synchronization, the One higher level's synchronization base station and second higher level's synchronization base station are also determined based on following manner：

If it is determined that having multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold value model When enclosing interior, it is first higher level's synchronization base station and the second higher level that at least two base stations are determined from that group of base station of synchronization level highest Synchronous base station；

Or if it is determined that there is multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold value In the range of when, determine in that group of base station maximum from two signal intensities at least two base stations for first higher level's synchronization base station and the Two higher level's synchronization base stations；

Or if it is determined that there is multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold value In the range of when, it is first higher level's synchronization base station that at least two base stations are determined from that group of base station with identical higher level's synchronization base station With second higher level's synchronization base station.
8. method according to claim 7, it is characterised in that determined in that group of base station maximum from two signal intensities At least two base stations are first higher level's synchronization base station and second higher level's synchronization base station, including：

If it is determined that having multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold value model In enclosing, and when having multigroup synchronization level highest base station, at least two base stations are determined in that group of base station maximum from signal intensity For first higher level's synchronization base station and second higher level's synchronization base station；

It is described to determine that at least two base stations are first higher level's synchronization base station from that group of base station with identical higher level's synchronization base station With second higher level's synchronization base station, including：

If it is determined that having multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold value model In enclosing, and when having multigroup synchronization level highest base station, determined at least from that group of base station with identical higher level's synchronization base station Two base stations are first higher level's synchronization base station and second higher level's synchronization base station；Or

If it is determined that having multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold value model In enclosing, and when having in multigroup synchronization level highest base station the maximum base station of multigroup signal intensity, from same with identical higher level Walk in that group of base station of base station and determine that at least two base stations are first higher level's synchronization base station and second higher level's synchronization base station.
9. method according to claim 8, it is characterised in that if the second higher level synchronization base station is used for Timing Synchronization, institute Stating method also includes：

Obtain the position that the second higher level synchronization base station sends synchronizing signal；

Multimedia broadcasting SFN MBSFN sub-frame is arranged on itself relevant position.
10. method according to claim 8, it is characterised in that if the second higher level synchronization base station is used for Timing Synchronization, institute Stating method also includes：

Obtain the position that the second higher level synchronization base station receives the synchronizing signal of its higher level's synchronization base station transmission；

MBSFN sub-frame is arranged on itself relevant position.
11. method according to claim 1, it is characterised in that the Timing Synchronization include initial timing synchronization and it is synchronous with Track.
A kind of 12. small base station, it is characterised in that including：

Determining module, for determining first higher level's synchronization base station for Timing Synchronization；

The determining module, it is additionally operable to determine at least one second higher level synchronization base station；

Processing module, if being used for the alternative of Timing Synchronization for the second higher level synchronization base station, when first higher level is same When step base station is not used to Timing Synchronization, synchronization is timed using the second higher level synchronization base station；

The processing module, if being additionally operable to the second higher level synchronization base station is also used for Timing Synchronization, on described first The synchronous base station of level and/or the second higher level synchronization base station are timed synchronization；

Judge module, for when base station link synchronous with first higher level fails, judging the first higher level synchronization base Station is not used to Timing Synchronization；Or when the first higher level synchronization base station base station link failure synchronous with its higher level, judge Go out the first higher level synchronization base station and be not used to Timing Synchronization；

If the second higher level synchronization base station is used for Timing Synchronization, the determining module is determined on described first based on following manner The synchronous base station of level and second higher level's synchronization base station：It is described first to determine at least two one group of base station with identical synchronization level Higher level's synchronization base station and second higher level's synchronization base station, and mutual synchronization timing error is in the range of preset threshold value；It is described It is identical that identical synchronization level is referred to as synchronous hop count.
13. the small base station according to claim 12, it is characterised in that if the second higher level synchronization base station is used for Timing Synchronization It is alternative, the determining module is specifically based on following manner and determines the second higher level synchronization base station：It is determined that with described first It is second higher level's synchronization base station that the synchronous base station of level, which has the base station of identical synchronization level,；Or determine that synchronization level highest base station is Second higher level's synchronization base station；Or determine that the maximum base station of signal intensity is second higher level's synchronization base station.
14. the small base station according to claim 13, it is characterised in that the determining module, for determining synchronization level highest Base station for second higher level's synchronization base station be specially if it is determined that base station not synchronous with first higher level has identical synchronization During the base station of grade, it is second higher level's synchronization base station to determine synchronization level highest base station；

The determining module, it is specially if it is determined that haunting for determining the maximum base station of signal intensity as second higher level's synchronization base station There is base station synchronous with first higher level that there is the base station of identical synchronization level or have multiple and the first higher level synchronization base station During base station with identical synchronization level, determine that the maximum base station of signal intensity is second higher level's synchronization base station；Or if it is determined that When base station not synchronous with first higher level has the base station of identical synchronization level and has multiple synchronization level highest base stations, Determine that the maximum base station of signal intensity is second higher level's synchronization base station.
15. the small base station according to claim 13, it is characterised in that if the second higher level synchronization base station is used for Timing Synchronization It is alternative, the determining module is additionally operable to：

Used if the second higher level synchronization base station is not used to Timing Synchronization or the second higher level synchronization upgrading base station to be current When the higher level synchronization base station of Timing Synchronization, the determination mode based on the second higher level synchronization base station determines new alternative higher level Synchronous base station.
16. the small base station according to claim 12, it is characterised in that if the second higher level synchronization base station is used for Timing Synchronization It is alternative, the small base station also includes：

Adjusting module, if there is the synchronization differed for the first higher level synchronization base station base station synchronous with second higher level Grade, and when the second higher level synchronization upgrading base station is the higher level synchronization base station for being currently used in Timing Synchronization, it is same to adjust itself Walk grade one-level lower than the synchronization level of the second higher level synchronization base station；

Control module, for controlling the base station using the small base station as higher level's synchronization base station correspondingly to adjust synchronization level.
17. according to any one of claim 13 to the 16 small base station, it is characterised in that if the second higher level synchronization base station is used In the alternative of Timing Synchronization, the small base station also includes：

Setup module, for setting and safeguarding alternative higher level's synchronization station list, in alternative higher level's synchronization station list Alternative higher level's synchronization base station synchronization grade is all identical and all identical with the synchronization level of the first higher level synchronization base station, or institute The alternative higher level's synchronization base station synchronization grade stated in alternative higher level's synchronization station list is different；

The determining module, for determining that at least one second higher level synchronization base station is specially to be based on the second higher level synchronization base The determination mode stood, determine that at least one alternative higher level's synchronization base station in alternative higher level's synchronization station list is on second The synchronous base station of level.
18. the small base station according to claim 13, it is characterised in that if the second higher level synchronization base station is used for timing together Step, the determining module also determine the first higher level synchronization base station and second higher level's synchronization base station based on following manner：If really Make multigroup base station with identical synchronization level and when mutual synchronization timing error is in the range of preset threshold value, from It is first higher level's synchronization base station and second higher level's synchronization base station that at least two base stations are determined in that group of base station of synchronization level highest； Or if it is determined that there is multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold value scope When interior, determine that at least two base stations are same for first higher level's synchronization base station and the second higher level in that group of base station maximum from signal intensity Walk base station；Or if it is determined that there is multigroup base station with identical synchronization level and mutual synchronization timing error is in preset threshold When in the range of value, it is first higher level's synchronization base that at least two base stations are determined from that group of base station with identical higher level's synchronization base station Stand and second higher level's synchronization base station.
19. the small base station according to claim 18, it is characterised in that the determining module, for maximum from signal intensity Determined in that group of base station at least two base stations for first higher level's synchronization base station and second higher level's synchronization base station be specially if it is determined that There is multigroup base station with identical synchronization level and mutual synchronization timing error is in the range of preset threshold value, and have multigroup During synchronization level highest base station, determine that at least two base stations are synchronous for the first higher level in that group of base station maximum from signal intensity Base station and second higher level's synchronization base station；

The determining module, for determining that at least two base stations are first from that group of base station with identical higher level's synchronization base station Higher level's synchronization base station and second higher level's synchronization base station are specially if it is determined that having multigroup base station with identical synchronization level and phase Synchronization timing error between mutually is in the range of preset threshold value, and when having multigroup synchronization level highest base station, from identical It is first higher level's synchronization base station and second higher level's synchronization base station that at least two base stations are determined in that group of base station of higher level's synchronization base station；

Or if it is determined that have multigroup base station with identical synchronization level and mutual error is in the range of preset threshold value, and When having the base station of multigroup signal intensity maximum in multigroup synchronization level highest base station, from identical higher level's synchronization base station It is first higher level's synchronization base station and second higher level's synchronization base station that at least two base stations are determined in that group of base station.
20. the small base station according to claim 17, it is characterised in that if the second higher level synchronization base station is used for timing together Step, the small base station also includes：

Acquisition module, the position of synchronizing signal is sent for obtaining the second higher level synchronization base station；

The setup module, for being arranged to multimedia broadcasting SFN MBSFN sub-frame on the small base station relevant position.
21. the small base station according to claim 17, it is characterised in that if the second higher level synchronization base station is used for timing together Step, the small base station also includes：

Acquisition module, the position for receiving the synchronizing signal of its higher level's synchronization base station transmission for obtaining the second higher level synchronization base station Put；

The setup module, for being arranged to MBSFN sub-frame on the small base station relevant position.