WO2009121204A1 - 在网关和基站之间进行同步的方法及相应的网关和基站 - Google Patents

在网关和基站之间进行同步的方法及相应的网关和基站 Download PDF

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Publication number
WO2009121204A1
WO2009121204A1 PCT/CN2008/000641 CN2008000641W WO2009121204A1 WO 2009121204 A1 WO2009121204 A1 WO 2009121204A1 CN 2008000641 W CN2008000641 W CN 2008000641W WO 2009121204 A1 WO2009121204 A1 WO 2009121204A1
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WIPO (PCT)
Prior art keywords
packet
synchronization period
synchronization
base station
burst
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PCT/CN2008/000641
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English (en)
French (fr)
Inventor
陈宇
泽勒·迪特里希
Original Assignee
上海贝尔阿尔卡特股份有限公司
阿尔卡特朗讯
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Application filed by 上海贝尔阿尔卡特股份有限公司, 阿尔卡特朗讯 filed Critical 上海贝尔阿尔卡特股份有限公司
Priority to PCT/CN2008/000641 priority Critical patent/WO2009121204A1/zh
Priority to US12/935,834 priority patent/US8493915B2/en
Priority to JP2011502207A priority patent/JP5225457B2/ja
Priority to CN200880128310.4A priority patent/CN101981874B/zh
Priority to EP08715073.6A priority patent/EP2262182B1/en
Priority to KR1020107024216A priority patent/KR101445115B1/ko
Publication of WO2009121204A1 publication Critical patent/WO2009121204A1/zh

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J3/00Time-division multiplex systems
    • H04J3/02Details
    • H04J3/06Synchronising arrangements
    • H04J3/0635Clock or time synchronisation in a network
    • H04J3/0638Clock or time synchronisation among nodes; Internode synchronisation
    • H04J3/0658Clock or time synchronisation among packet nodes
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/12Wireless traffic scheduling
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/30Resource management for broadcast services

Definitions

  • the present invention relates to synchronization techniques in mobile communications, and in particular to a method of synchronizing between a gateway and a base station and a corresponding gateway and base station.
  • the 3GPP (3rd Generation Partnership Project) launched the Long Term Evolution Research Project (LTE) in 2005, hoping to support the growing needs of operators and users with higher data throughput and better network performance. '
  • Multimedia Broadcast/Multicast Service is a service introduced by 3GPP Rel6. It refers to a point-to-multipoint service where a data source sends data to multiple users, thereby realizing resource sharing of the network (including core network and access network). To achieve as many services as possible for multimedia users with the same needs with as few resources as possible.
  • the MBMS service can realize low-rate message-like multicast and broadcast, and can also realize multicast and broadcast of higher-rate multimedia services by using a common transport channel and a public radio bearer, for example, Mobile TV.
  • the core network adopts a two-layer flat network architecture, that is, four major network elements of the original WCDMA/HSDPA phase, such as NodeB, RNC, SGSN, and GGSN, evolve into an eNodeB (eNB). That is, the evolved base station (hereinafter referred to as 'base station'), and the access gateway (GW) are two main network elements, and the core network adopts an all-IP distributed structure, and supports IMS, VoIP, SIP, Mobi le IP, and the like.
  • eNB evolved base station
  • GW access gateway
  • Figure 1 shows the structure of a network in LTE.
  • the access gateway GW receives data from the BM-SC (Broadcast Multicast Service Center). And the access gateway GW is connected to a plurality of base stations eN1, eNB2 and eNB3, and the user plane interface between them is called an M1 interface.
  • the plurality of base stations eNB are connected in the form of a mesh (dashed line in Fig. 1), and the interface between the base stations eNB is called an X2 interface.
  • a plurality of user equipments UE11 to E12, UEs 21 to 23, and UEs 31 to 33 are schematically shown in the respective cells of the base stations eNB1 to 1-3.
  • the physical layer downlink transmission scheme of the radio interface adopts OFDM
  • the uplink transmission scheme adopts SC-FDMA technology. Due to the adoption of the 0FDM system, the same wireless signals in different cells can Natural integration in the air to increase signal strength without additional processing overhead, ie RF combining:.
  • the base station eNB in the SFN has reached synchronization at the frame timing of the physical layer, and the accuracy has already met the requirements for radio combining of EMBMS.
  • the combined wireless signals must be required to be synchronized and consistent in the content of the MBMS service. That is to say, the transmission of Layer 2 (L2) is also guaranteed in the multi-cell transmission of the MBMS service.
  • IP multicast IP Mult icast
  • IP Multicast IP Multicast
  • an MBMS service packet is sent once to a group of base station eNBs.
  • the current IP multicast routing protocol stipulates that the route between each base station eNB and the access gateway GW mainly depends on the current network topology, and remains unchanged, unless the relevant router is damaged, but this rarely happens. .
  • the processing power of the routers in the network and the transmission load of the network are optimized for network optimization. Therefore, the main factors affecting the different transmission delays on different transmission paths from the base station eNB to the access gateway GW are usually only different transmission paths. That is, although the base station eNB has already synchronized at the physical layer's frame timing in the SFN area, the same MBMS data packet may arrive at a different base station eNB at different times due to different routes.
  • Figure 2 is a diagram for explaining the delay of the same data packet transmitted from the access gateway to different base stations.
  • the same data packet will have different delays after different transmission paths.
  • the data is grouped at T.
  • a method of storing the received data in the cache for a period of time and then scheduling is performed. For example, if a packet is transmitted from the gateway to two base stations simultaneously, the time to arrive at one base station is 7:55, and the time to arrive at another base station is 8:01, since both base stations store the received packets in There is a period of time in the buffer, so when the two base stations subsequently send packets (e.g., 8:30), they can be guaranteed to send packets of the same content at the same time.
  • SFN single frequency network
  • the base station takes the received data in the cache and uses the first-in first-out method to take out the head of the team after a certain period of time (ie, The data that is first entered into the cache is scheduled to ensure synchronization of data content scheduled by different base stations at the same time.
  • the above prior art has the following deficiencies for the needs of the service multiplexing and synchronization: As described above, due to various network delays and other delays, the same data packets arrive at each base station from the gateway at different times. . Although the prior art can ensure the synchronization of the data of the cache heads between the base stations by buffering the data packets, it cannot guarantee that the corresponding data of the respective services received between the base stations are kept synchronized.
  • the present invention has been accomplished in view of the above problems.
  • the object of the present invention is to provide a method for synchronizing between a gateway and a base station, and a corresponding gateway and base station, which can ensure that corresponding data of each service received by each base station is kept synchronized to meet service multiplexing and synchronization. Demand.
  • a method of synchronizing between a gateway and a base station comprising the steps of:
  • a synchronization period corresponding to a packet to be sent to the base station where the synchronization period is used as a scheduling granularity of the base station, adding information indicating the synchronization period to a header portion of the packet, and sending the packet To corresponding multiple base stations;
  • the synchronization period corresponding to the packet is learned, and the packet is stored in the cache.
  • the synchronization period that is terminated before the scheduling is determined according to the synchronization period corresponding to the stored packet, and the packet corresponding to the determined synchronization period is scheduled according to a predetermined scheduling policy.
  • the condition for judging whether or not it can be scheduled is whether a certain synchronization period is terminated before the scheduling time. Since the synchronization period is synchronized between the gateway and the base station, it is easy for the base station to know whether a certain synchronization period is terminated before scheduling, and the judgment criterion is the end time of the synchronization period + the pre-estimated margin.
  • the method may further include the step of: setting a sequence of the synchronization period according to a same time reference at each of the gateway and each of the plurality of base stations.
  • the step of adding information indicating the synchronization period to a header portion of the packet may further include: if the packet is the first packet in a burst, to the packet a time stamp identifying a synchronization period corresponding to a time at which the packet is received, and information identifying a synchronization period of the packet in the burst and a cumulative count of all previous synchronization periods in the burst If the packet is a subsequent packet in a burst, adding the first packet in the burst to which the packet belongs to the header portion of the packet A corresponding timestamp, and information identifying a synchronization period to which the packet belongs in the burst and a cumulative count of all previous synchronization periods in the burst.
  • the step of adding, to the header portion of the packet, a timestamp indicating a synchronization period corresponding to the time when the packet is received may further include: time when the packet is received The predetermined delay estimators are added, a corresponding synchronization period is determined based on the added result time, and a time stamp identifying the determined synchronization period is added to the header portion of the packet.
  • the step of obtaining the synchronization period corresponding to the packet according to the information in the header portion of the packet may further include: according to a timestamp included in a header portion of the packet, Determining a synchronization period corresponding to the first packet of the burst to which the packet belongs; and determining, according to the determined synchronization period corresponding to the first packet, and the identifier included in a header portion of the packet.
  • the information of the accumulated count of the synchronization period corresponding to the synchronization period is used to determine the synchronization period corresponding to the packet.
  • the information indicating the synchronization period may further include information indicating a number of the synchronization period in a sequence of the synchronization period set in advance.
  • the determining, according to the synchronization period corresponding to the stored packet, the synchronization period that is terminated before the scheduling may further include: determining, according to the number of the synchronization period corresponding to the stored packet, the scheduling The synchronization period having the largest number among the synchronization periods ending before the time when the predetermined delay estimate is subtracted from the time, the determined synchronization period and the synchronization period before the determined synchronization period are taken as the synchronization terminated before the scheduling Time period.
  • the method may further include: at the gateway, pre-configuring information indicating a maximum number of synchronization periods corresponding to each burst, and, according to the information, duration exceeding the The burst of the maximum number of synchronization periods is split into two or more bursts.
  • the method may further include: at the gateway: if the packet to be sent to the multiple base stations is not received within a predetermined period of time, to construct and send to the multiple base stations A dummy packet that does not include a payload; and at each base station of the plurality of base stations, after receiving the packet, determining the end of the previously received burst based on the timestamp included in the packet.
  • a gateway including: receiving means for receiving a packet to be sent to a base station; and processing means for determining a packet received by the receiving means Corresponding synchronization period, and adding information indicating the synchronization period to the header portion of the packet, the synchronization period serving as a scheduling granularity of the base station; and transmitting means for transmitting the processing device processing to the plurality of base stations After the grouping.
  • the apparatus may further include: setting means, configured to set a sequence of the synchronization period in advance according to the same time reference as the plurality of base stations.
  • the processing device may further add, to the header portion of the packet, a timestamp corresponding to the first packet in the burst to which the packet belongs, and identify the burst.
  • the apparatus may further include: splitting means, configured to allow information about the maximum number of synchronization periods corresponding to each burst according to the pre-configured indication, and the duration received by the receiving apparatus exceeds The burst of the maximum number of synchronization periods is split.
  • the method further includes: a fake packet sending apparatus, configured to: if not, the packet to be sent to the multiple base stations is not received, and configured to send to the multiple base stations, not including A fake grouping of payloads.
  • a fake packet sending apparatus configured to: if not, the packet to be sent to the multiple base stations is not received, and configured to send to the multiple base stations, not including A fake grouping of payloads.
  • a base station including: a buffer for storing a packet; a receiving device, configured to receive a packet from a gateway; and processing means, configured to receive, according to the packet received by the receiving device The information in the header portion to learn the synchronization period corresponding to the packet, and store the packet in the buffer; and scheduling means for, according to the buffer, when scheduling is required
  • the synchronization period corresponding to the packet stored in the packet determines a synchronization period that is terminated before the scheduling, and schedules and transmits the packet corresponding to the determined synchronization period according to a predetermined scheduling policy.
  • the setting device may be further configured to set the sequence of the synchronization period in advance according to the same time reference as the gateway.
  • the processing device may further determine, according to the timestamp included in the header portion of the packet, a synchronization period corresponding to the first packet of the burst to which the packet belongs, and according to the determined Determining the synchronization period corresponding to the first packet, and information included in a header portion of the packet that identifies a synchronization period of the packet in the burst and a cumulative count of all previous synchronization periods The synchronization period corresponding to the group.
  • the scheduling apparatus may further determine, according to the number of the synchronization period corresponding to the stored packet, that the synchronization period ending before the timing of subtracting the predetermined delay estimation amount from the scheduling moment has the largest number. a synchronization period, and the determined synchronization period and the synchronization period before the determined synchronization period are used as the synchronization period that is terminated before scheduling.
  • the scheduling apparatus may also clear all unsent data of the previous burst stored in the buffer before scheduling the new burst packet.
  • At least one of the foregoing technical solutions achieves synchronization of corresponding data of respective services received between the base stations by changing the scheduling granularity.
  • the problem with the prior art described above is that the scheduling granularity is too small, such as a data packet or a frame (10 ms), and the uncertainty is apt to occur because the granularity is too short.
  • the gateway side and the base station side can determine the received data according to the consistent synchronization period, thereby causing the respective base stations
  • the boundary of the received data to be scheduled can be determined according to the consistent synchronization period, that is, the synchronization period can be used as a consistent scheduling granularity of each base station, for example, 320 ms, so it is easy to determine the sequence relationship and receive a few
  • the data of the synchronization period so that the corresponding data of each service received between the base stations can be synchronized, and the requirements of service multiplexing and synchronization are satisfied.
  • Figure 1 shows the structure of a network in LTE
  • FIG. 2 is a schematic diagram for explaining a delay of transmission of the same data packet from an access gateway to a different base station
  • Embodiment 3 is a flow chart of Embodiment 1 of a method of synchronizing between a gateway and a base station according to the present invention
  • Embodiment 4 is a schematic diagram of Embodiment 1 of a method for synchronizing between a gateway and a base station according to the present invention
  • FIG. 5 is another schematic diagram of Embodiment 1 of a method of synchronizing between a gateway and a base station in accordance with the present invention
  • Figure 6 is a block diagram showing the structure of a gateway according to the present invention
  • Figure 7 is a block diagram showing the structure of a base station according to the present invention. detailed description
  • the embodiment includes - performing the following steps at the gateway: At step S1, determining a synchronization period corresponding to a packet to be transmitted to the base station, the synchronization period serving as a scheduling granularity of the base station; At S2, adding information indicating the synchronization period to a header portion of the packet; then, at step S3, transmitting the packet to a corresponding plurality of base stations;
  • step S4 after receiving the packet, learning, according to the information in the header portion of the packet, a synchronization period corresponding to the packet. Then, at step S5, the packet is stored in the buffer; then, at step S6, when the scheduling is required, the synchronization period terminated before the scheduling is determined according to the synchronization period corresponding to the stored packet; At step S7, the packet corresponding to the determined synchronization period is scheduled in accordance with a predetermined scheduling policy.
  • the corresponding data of each service received between the base stations is kept synchronized by changing the scheduling granularity.
  • the problem with the prior art described above is that the scheduling granularity is too small, such as a data packet or a frame (10 ms), and the uncertainty is apt to occur because the granularity is too short.
  • the prior art can ensure the synchronization of the data of the cache heads between the base stations by buffering the data packets, it cannot guarantee that the corresponding data of the respective services received between the base stations are kept synchronized.
  • the gateway side and the base station side can determine the boundary of the received data to be scheduled according to the consistent synchronization period reference. Synchronization of scheduling of respective data between respective base stations for respective services, so that the synchronization period can be used as a uniform scheduling granularity of each base station, such as 320 ms, so that the base station can easily determine the sequence time relationship and receive several synchronizations.
  • the data of the time period so as to ensure the synchronization of the data of the cached heads between the base stations, and also the data of the synchronized time periods that have been determined to be scheduled, to ensure the respective services received between the base stations.
  • the sequence of the synchronization period may be set in advance at the base station and each of the plurality of base stations according to the same time reference, thereby enabling each base station to be The baseline for the synchronization period remains the same.
  • the step of adding information indicating the synchronization period to a header portion of the packet may include: if the packet is the first packet in a burst, to the packet a header time portion identifying a synchronization period corresponding to the time at which the packet is received, and information identifying a synchronization period of the packet in the burst and a cumulative count of all previous synchronization periods, if the grouping Is a subsequent packet in a burst, adding a timestamp corresponding to the first one of the bursts to which the packet belongs to the header portion of the packet, and identifying the packet to which the burst belongs The synchronization period and the accumulated count information of all previous synchronization periods.
  • Protocol Data Unit (PDU) after adding the timestamp and corresponding counting information
  • the "list length” field is the number of synchronization periods experienced by the burst, that is, the length of the list indicating the ⁇ byte count, packet count ⁇ .
  • the "List of ⁇ Byte Count, Packet Count ⁇ ” field is the byte count and packet count for each sync period of the burst.
  • the total byte count for this burst (to date) the sum of all the byte counts in the list
  • Total Packet Count for this burst (to date) the sum of all packet counts in this list.
  • the time stamp in the above first example is based on the granularity of the synchronization period, which is set on the user plane M1 interface between the gateway and the base station, and is specific to each E-MBMS.
  • An example of the size of the sync period is 500ms.
  • a burst can include one or more SYNC periods.
  • the first example and the second example are used as examples only and are not intended to limit the present invention. Those skilled in the art should understand that the protocol after adding the time stamp and the corresponding counting information can be flexibly set according to the requirements of the actual application scenario.
  • the specific format of the Data Unit (PDU) should be within the scope of the claims of the present invention.
  • the step of adding a timestamp indicating the synchronization period corresponding to the time when the packet is received to the header portion of the packet may include: receiving the The time of the packet is added to a predetermined delay estimator, a corresponding synchronization period is determined according to the added result time, and a time stamp identifying the determined synchronization period is added to a header portion of the packet.
  • the step of obtaining the synchronization period corresponding to the packet according to the information in the header portion of the packet may include: determining, according to a timestamp included in a header portion of the packet, a synchronization period corresponding to the first packet of the burst to which the packet belongs, and a synchronization period corresponding to the determined first packet, and an identifier included in a header portion of the packet.
  • the information of the cumulative count of the corresponding synchronization period is used to determine the synchronization period corresponding to the packet.
  • the information indicating the synchronization period may include information indicating a number of the synchronization period in a sequence of the synchronization period set in advance.
  • the determining, according to the synchronization period corresponding to the stored packet, the synchronization period that is terminated before the scheduling may include: determining, according to the number of the synchronization period corresponding to the stored packet, the scheduling The synchronization period having the largest number among the synchronization periods ending before the time when the predetermined delay estimate is subtracted from the time, the determined synchronization period and the synchronization period before the determined synchronization period are taken as the synchronization terminated before the scheduling Time period.
  • the base station can know which synchronization period the packet belongs to according to the "list length" field included in the received packet. . For example, if the timestamp is K-1 and the value of the "list length" field in the received packet is 2, the base station can know that the packet belongs to the synchronization period 1 (.
  • the base station after determining the specific synchronization period to which the packet belongs, the base station will schedule the packet only at a time T not earlier than the specific synchronization period, that is, the synchronization period indicates the processing for the base station. The earliest time.
  • the scheduling period used may be consistent with the synchronization period, or the synchronization period may be an integer multiple of the scheduling period.
  • the first case shows that the scheduling period of the base station is approximately synchronized with the synchronization periods K1, ⁇ , K+l (possibly with a smaller offset), which is the optimal case;
  • the two cases show that the scheduling period of the base station is a non-integer multiple of the synchronization period, the synchronization period is subject to a longer delay, which is not optimal;
  • the third case shows that the scheduling period of the base station is the synchronization period In the case of non-integer multiples, this is not optimal.
  • the unscheduled data of the base station in one scheduling period may be incorporated into the next scheduling period for scheduling.
  • the method may further include: at the gateway, pre-configuring information indicating a maximum number of synchronization periods allowed for each burst, and according to the information, the duration exceeds The burst of the maximum number of synchronization periods is split into two or more bursts.
  • the method may further include: at the gateway: if the packet to be sent to the multiple base stations is not received within a predetermined period of time, to construct and direct to the multiple base stations A dummy packet not including a payload is transmitted, and at each base station of the plurality of base stations, after receiving the packet, determining the end of the previously received burst based on the timestamp included in the packet.
  • a gateway is also provided. FIG.
  • Embodiment 1 of a gateway is a schematic structural diagram of Embodiment 1 of a gateway according to the present invention.
  • the embodiment includes: a receiving device 61, configured to receive a packet sent to the base station; the processing device 62, configured to determine a synchronization period corresponding to the packet received by the receiving device 61, and add information indicating the synchronization period to a header portion of the packet, where the synchronization period is used a scheduling granularity of the base station; and transmitting means 63, configured to send the processed packet by the processing device to the plurality of base stations.
  • the apparatus may further include: setting means, configured to set a sequence of the synchronization period in advance according to the same time reference as the plurality of base stations.
  • the processing device may add, to the header portion of the packet, a timestamp corresponding to the first packet in the burst to which the packet belongs, and identify the burst.
  • Information indicating a synchronization period to which the packet belongs and a cumulative count of all previous synchronization periods belonging to the burst, wherein the time stamp indicates a synchronization period corresponding to the time at which the first packet was received.
  • the method further includes: splitting means, for receiving, according to the pre-configured indication, information about the maximum number of synchronization periods corresponding to each burst, the duration received by the receiving device 61 A burst that exceeds the maximum number of synchronization periods is split.
  • the method further includes: a fake packet sending apparatus, configured to: if not, the packet to be sent to the multiple base stations is not received, and configured to send to the multiple base stations Includes a fake grouping of payloads.
  • a fake packet sending apparatus configured to: if not, the packet to be sent to the multiple base stations is not received, and configured to send to the multiple base stations Includes a fake grouping of payloads.
  • the corresponding data of each service received between the base stations is kept synchronized by changing the scheduling granularity.
  • the problem with the prior art described above is that the scheduling granularity is too small, such as a data packet or a frame (10 ms), and the uncertainty is apt to occur because the granularity is too short.
  • the gateway side and the base station side can determine the boundary of the received data to be scheduled according to the consistent synchronization period, thereby
  • the synchronization period can be used as a scheduling granularity of the base station in the subsequent processing of the base station, for example, 320 ms, so that the base station can easily determine the sequence time relationship and receive data of several synchronization periods, thereby enabling mutual base stations to be realized.
  • the corresponding data of each received service is kept synchronized to meet the requirements of service multiplexing and synchronization.
  • FIG. 7 is a schematic structural diagram of Embodiment 1 of a base station according to the present invention.
  • the embodiment includes: a buffer 71 for storing a receiving unit 72, configured to receive a packet from the gateway, and a processing device 73, configured to learn, according to the information in the header portion of the packet received by the receiving device 72, a synchronization period corresponding to the packet And storing the packet in the buffer 71; and scheduling means 74, configured to determine to terminate before scheduling according to a synchronization period corresponding to the packet stored in the buffer 71 when scheduling is required The synchronization period, and scheduling and transmitting the packet corresponding to the determined synchronization period according to a predetermined scheduling policy.
  • the method may further include: setting means for setting the sequence of the synchronization period in advance according to the same time reference as the gateway.
  • the processing device may determine, according to a timestamp included in a header portion of the packet, a synchronization period corresponding to a first packet of a burst to which the packet belongs, and according to the determined Determining the grouping by a synchronization period corresponding to the first packet, and information included in a header portion of the packet that identifies a synchronization period of the packet in the burst and a cumulative count of all previous synchronization periods The corresponding synchronization period.
  • the scheduling apparatus may determine, according to the number of the synchronization period corresponding to the stored packet, that the synchronization period that ends before the timing of subtracting the predetermined delay estimation amount from the scheduling time has the largest number.
  • the synchronization period is performed, and the determined synchronization period and the synchronization period before the determined synchronization period are taken as the synchronization period that is terminated before the scheduling.
  • the scheduling apparatus may clear all data of the previous burst stored in the buffer before scheduling the new burst packet.
  • the corresponding data of each service received between the base stations is kept synchronized by changing the scheduling granularity.
  • the problem with the prior art described above is that the scheduling granularity is too small, such as a data packet or a frame (10 ms), and the uncertainty is apt to occur because the granularity is too short.
  • the gateway side and the base station side can determine the boundary of the received data to be scheduled according to the consistent synchronization period.
  • Data is kept in sync to meet the needs of business reuse and synchronization.

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Description

在网关和基站之间进行同步的方法及相应的网关和基站 技术领域
本发明涉及移动通信中的同步技术,具体地,涉及一种在网关和基站之 间进行同步的方法及相应的网关和基站。 背景技术
3GPP (第三代合作伙伴计划)在 2005年启动了长期演进研究项目(LTE), 希望以更高的数据吞吐量和更好的网络性能,为运营商和用户不断增长的需 求提供支持。 '
多媒体广播 /组播业务 (MBMS ) 是 3GPP Rel6引入的一项业务, 是指一 个数据源向多个用户发送数据的点到多点业务,从而实现网络(包括核心网 和接入网)资源共享, 以尽可能少的资源实现对尽可能多的、具有相同需求 的多媒体用户的服务。在无线接入网, MBMS业务通过使用公共传输信道和公 共无线承载, 既能实现纯文本低速率的消息类组播和广播, 也能实现较高速 率的多媒体业务的组播和广播, 例如, 手机电视。
目前, 关于 EMBMS (演进的 MBMS ) 的各项研究正在进行中。
在 3GPP的长期演进(LTE) 中, 核心网采用两层扁平网络架构, 也就是 由原来的 WCDMA/HSDPA阶段的 NodeB、 RNC、 SGSN和 GGSN四个主要的网络单元, 演进为 eNodeB ( eNB), 即演进型基站(下面简称 '基站 '), 和接入网关(GW) 两个主要的网络单元, 并且核心网采用全 IP分布式结构, 支持 IMS、 VoIP, SIP和 Mobi le IP等等。
图 1示出了 LTE中网络的结构。接入网关 GW从 BM-SC (广播组播服务中心) 接收数据。 并且接入网关 GW与多个基站 eNl, eNB2和 eNB3连接, 它们之间的 用户面接口称为 Ml接口。上述的多个基站 eNB之间以网格(mesh )的形式(图 1中的虚线) 连接, 基站 eNB之间的接口称为 X2接口。 基站 eNBl〜3的各个小 区中示意性地显示了多个用户设备 UE11〜E12, UE21〜23以及 UE31〜33。
LTE中, 无线接口的物理层下行传输方案采用 OFDM, 而上行传输方案采 用 SC- FDMA技术。 由于采用了 0FDM体制, 不同小区中相同的无线信号能够在 空中进行自然的合并以提升信号强度,而无需额外的处理开销, 即可以进行 射频合并 ( RF combining:)。
因此, 对于 LTE中的 EMBMS来说, 支持在单频网 (SFN ) 多小区传输模式 下的空中射频合并来提高小区边界的增益己经被定义为一个基线 ( baseline )需求, 因为 EMBMS需要将同一业务数据发送给不同的多个用户。
在 SFN中的基站 eNB已经在物理层的帧定时上达到了同步, 并且精度已 经可以满足 EMBMS的射频合并的要求。 但是, 为了保证射频合并的有效性, 必须要求被合并的无线信号在 MBMS业务的内容上保持同步和一致性。也就是 说, 在 MBMS业务的多小区发送上还要保证第 2层 (L2 ) 的传输同步。
此外, 在 LTE的网络架构设计中, IP组播 (IP Mult icast ) 传输已经被 扩展到了基站 eNB。 利用 IP Multicast , 一个 MBMS业务分组会被发送一次到 一组基站 eNB。当前的 IP multicast路由协议规定了每个基站 eNB到接入网关 GW之间的路由主要依赖于当前的网络拓扑结构, 并且保持不变, 除非有相关 的路由器损坏了, 但是这种情况很少发生。 另外, 网络中的路由器的处理能 力以及网络的传输负载在进行网络优化的时候会进行优化。所以,影响在基 站 eNB到接入网关 GW的不同传输路径上不同传输时延的主要因素通常就只有 不同的传输路径。也就是说,尽管在 SFN区域中基站 eNB在物理层的帧定时上 已经同步了,但是由于不同的路由也会导致相同的 MBMS数据分组在不同的时 间到达不同的基站 eNB。
图 2是用来说明相同的数据分组从接入网关传输到不同的基站的时延 的示意图。 如图 2所示, 从接入网关 GW传输到基站 eNBl的数据分组所经过的 路由是:接入网关 GW= =〉路由器 Rl = =〉基站 eNBl。从接入网关 GW传输到基 站 eNB2的数据分组所经过的路由是接入网关 GW= = >路由器 R2 = = >路由器 R3 = =〉基站 eNB2。相同数据分组经过不同的传输路径必然产生不同的时延。
如图 2所示, 数据分组在 T。时刻同时从接入网关 GW向基站 eNBl和 eNB2传 输, 到达基站 eNBl的时刻是 1\, 而到达基站 eNB2的时刻是 T2。 因此相同的数 据分组到达不同的基站 eNB就出现了相对时延 TD = T2-T,。
由上述可知, 如果基站 eNBl和 eNB2接收到接入网关 GW发来的数据分组 后马上就发送出去, 很明显, 相同内容的数据分组在不同的基站 eNB被异步 地发送给用户设备 UE。这必然导致这些数据分组不能被正确地合并,甚至会 造成额外的干扰。 此外, 同一个数据分组在到达基站 eNB后, 每个基站 eNB 需要对其进行分段、编码和调制成帧等处理,不一致的成帧处理时间也会影 响到这些数据的射频合并。
因此, 现有技术中, 为了满足单频网 (SFN)对多个基站在同一时间同 一频率上发送相同内容的信号的需求,采用将接收的数据在缓存中存储一段 时间后再进行调度的方法, 例如, 如果分组从网关同时向两个基站传输, 到 达一个基站的时间是 7: 55, 而到达另一基站的时间是 8: 01, 则由于这两个 基站均将收到的分组存储在缓存中一段时间,因此在这两个基站随后发送分 组 (例如 8: 30 ) 时, 能够保证它们在相同时间发送相同内容的分组。
上述仅仅是一个示意性示例, 旨在说明现有技术中实现单频网需求的 方法, 即, 基站通过将接收的数据放入缓存, 并在一定时间后采用先入先出 方式取出队首(即最先进入缓存)的数据来进行调度, 能够保证不同基站在 同一时间所调度的数据内容同步。
但是, 随着通信技术的发展和 3G标准的研发, 提出了业务复用的新需 求, 即多个 EMBMS业务动态的共享同一块时频资源, 并且每个业务所占用的 资源份额由各个基站独立分配。 同时, 为保证单频网的要求, 各个基站之间 对各个业务的资源分配结果必须保持一致。 为了满足上述服用要求, 3GPP 首先引入了调度周期的概念。每个基站有着同步的调度周期,一个调度周期 内的资源也是相同的。 针对一个调度周期, 基站只调度一次。 调度时, 基站 根据缓存的数据,可用的共享资源以及特定的调度算法等向各个业务分配相 应的资源。
针对于该业务复用和同步的需求, 上述现有技术存在以下不足之处: 如上文所述, 由于各种网络延迟和其它时延, 相同的数据分组从网关 到达各个基站的时间并不相同。虽然现有技术通过缓存数据分组能够保证各 基站之间的缓存队首的数据的同步,但是却不能保证各基站之间所接收到的 各个业务的相应数据保持同步。
例如, 一个基站缓存的数据中针对 A业务的数据为 100bit, 而另一基站 缓存的数据中针对 A业务的数据为 200bit,则这两个基站对 A业务的数据的资 源分配难以做到同步, 也即不能满足上述业务复用和同步的需求。 发明内容
鉴于上述问题,完成了本发明。本发明的目的是提出一种在网关和基站 之间进行同步的方法以及相应的网关和基站,能够保证各基站之间所接收到 的各个业务的相应数据保持同步, 以满足业务复用和同步的需求。
根据本发明的一个方面, 提出了一种在网关和基站之间进行同步的方 法, 包括以下步骤:
在网关处, 确定要发送至基站的分组所对应的同步时段, 所述同步时 段用作基站的调度粒度,向所述分组的报头部分中添加指示所述同步时段的 信息, 将所述分组发送至对应的多个基站; 以及
在所述多个基站的每个基站处, 在接收到所述分组之后, 根据所述分 组的报头部分中的所述信息,获知所述分组所对应的同步时段,将所述分组 存储在缓存器中,在需要进行调度时,根据所存储的分组所对应的同步时段, 确定在调度之前终止的同步时段,按照预定的调度策略,对与所确定的同步 时段相对应的分组进行调度。
上述技术方案中, 因为还需要根据后面的分组携带的字节计数和分组 计数的列表,来査看前一个同步时段的数据是否都收到了以及丢失了多少数 据。 即使某个同步时段的数据有些丢失了, 只要知道丢失了多少字节, 多少 个数据包,还是可以保持调度同步的。所以判断能不能调度的条件是某个同 步时段是不是在调度时刻之前就终止了。因为同步时段在网关和基站之间都 是同步的,所以基站很容易知道某个同步时段是否在调度前终止, 判断标准 就是同步时段的结束时间 +预先估计的余量。
优选地, 上述技术方案中, 还可包括以下步骤: 预先在所述网关和所 述多个基站的每个基站处分别按照同一时间基准来设置所述同步时段的序 列。
优选地, 上述技术方案中, 向所述分组的报头部分中添加指示所述同 步时段的信息的步骤还可包括: 如果所述分组是一个突发中的第一个分组, 则向所述分组的报头部分中添加标识接收到所述分组的时间所对应的同步 时段的时间戳、以及标识所述突发中所述分组所属同步时段以及所述突发中 先前所有同步时段的累计计数的信息;如果所述分组是一个突发中的后续分 组,则向所述分组的报头部分中添加所述分组所属于的突发中的第一个分组 所对应的时间戳、以及标识所述突发中所述分组所属同步时段以及所述突发 中先前所有同步时段的累计计数的信息。
优选地, 上述技术方案中, 所述向所述分组的报头部分中添加标识接 收到所述分组的时间所对应的同步时段的时间戳的步骤还可包括:将接收到 所述分组的时间与预定的时延估计量相加,根据所述相加的结果时间确定对 应的同步时段,以及向所述分组的报头部分中添加标识所确定的同步时段的 时间戳。
优选地, 上述技术方案中, 所述根据所述分组的报头部分中的所述信 息获知所述分组所对应的同步时段的步骤还可包括:根据所述分组的报头部 分中包括的时间戳,确定所述分组所属的突发的第一个分组所对应的同步时 段; 以及根据所确定的所述第一个分组所对应的同步时段、 以及所述分组的 报头部分中包括的标识所述突发所对应的同步时段的累计计数的信息,来确 定所述分组所对应的同步时段。
优选地, 上述技术方案中, 所述指示所述同步时段的信息还可包括指 示所述同步时段在预先设置的所述同步时段的序列中的编号的信息。
优选地, 上述技术方案中, 所述根据所存储的分组所对应的同步时段 确定在调度之前终止的同步时段的步骤还可包括:根据所存储的分组所对应 的同步时段的编号,确定在调度时刻减去预定的时延估计量的时刻之前结束 的同步时段中具有最大编号的同步时段,将所确定的同步时段及在所确定的 同步时段之前的同步时段作为所述在调度之前终止的同步时段。
优选地, 上述技术方案中, 还可包括以下步骤: 在所述网关处, 预先 配置指示允许每个突发所对应的最大同步时段数量的信息,以及根据所述信 息, 将持续时间超过所述最大同步时段数量的突发拆分为两个或更多个突 发。
优选地, 上述技术方案中, 还可包括以下步骤: 在所述网关处: 如果 在预定时期内未接收到要发送至所述多个基站的分组,则以构造并向所述多 个基站发送不包括有效载荷的假分组; 以及在所述多个基站的每个基站处, 在接收到分组后, 根据分组中包括的时间戳来确定先前接收的突发的结束。
根据本发明的另一方面, 还提供了一种网关, 包括: 接收装置, 用于 接收要发送至基站的分组; 处理装置,用于确定所述接收装置接收的分组所 对应的同步时段, 并向所述分组的报头部分中添加指示所述同步时段的信 息, 所述同步时段用作基站的调度粒度; 以及发送装置, 用于向多个基站发 送所述处理装置处理后的分组。
优选地, 上述技术方案中, 还可包括: 设置装置, 用于预先按照与所 述多个基站相同的时间基准来设置所述同步时段的序列。
优选地, 上述技术方案中, 所述处理装置还可向所述分组的报头部分 中添加所述分组所属于的突发中的第一个分组所对应的时间戳、以及标识所 述突发中所述分组所属同步时段以及所述突发中先前所有同步时段的累计 计数的信息,其中所述时间戳指示了接收到所述第一个分组的时间所对应的 同步时段。
优选地, 上述技术方案中, 还可包括拆分装置, 用于根据预先配置的 指示允许每个突发所对应的最大同步时段数量的信息,对所述接收装置接收 到的、 持续时间超过所述最大同步时段数量的突发进行拆分。
优选地, 上述技术方案中, 还可包括假分组发送装置, 用于如果在预 定时期内未接收到要发送至所述多个基站的分组,则以构造并向所述多个基 站发送不包括有效载荷的假分组。
根据本发明的另一方面, 还提供了一种基站, 包括: 缓存器, 用于存 储分组; 接收装置, 用于接收来自网关的分组; 处理装置, 用于根据所述接 收装置所接收的分组的报头部分中的所述信息,来获知所述分组所对应的同 步时段, 并将所述分组存储在所述缓存器中; 以及调度装置, 用于在需要进 行调度时,根据所述缓存器中存储的分组所对应的同步时段,来确定在调度 之前终止的同步时段, 并按照预定的调度策略,对与所确定的同步时段相对 应的分组进行调度和发送。
优选地, 上述技术方案中, 还可包括设置装置, 用于预先按照与所述 网关相同的时间基准来设置所述同步时段的序列。
优选地, 上述技术方案中, 所述处理装置还可根据所述分组的报头部 分中包括的时间戳,确定所述分组所属的突发的第一个分组所对应的同步时 段, 并根据所确定的所述第一个分组所对应的同步时段、以及所述分组的报 头部分中包括的标识所述突发中所述分组所属同步时段以及先前所有同步 时段的累计计数的信息, 来确定所述分组所对应的同步时段。 优选地, 上述技术方案中, 所述调度装置还可根据所存储的分组所对 应的同步时段的编号,确定在调度时刻减去预定的时延估计量的时刻之前结 束的同步时段中具有最大编号的同步时段,并将所确定的同步时段及在所确 定的同步时段之前的同步时段作为所述在调度之前终止的同步时段。
优选地, 上述技术方案中, 所述调度装置还可在调度新的突发的分组 之前, 清空所述缓存器中存储的先前的突发的未发送的所有数据。
上述技术方案中的至少一个技术方案通过改变调度粒度来实现各基站 之间所接收到的各个业务的相应数据保持同步。上文所述现有技术的问题在 于调度粒度太小, 比如一个数据包或一帧(10ms), 由于颗粒度太短就容易出 现不确定性。根据本发明的至少一个方面的技术方案, 由于在网关侧和基站 侧同时引入了同步时段的概念,使得网关侧和基站侧能够根据一致的同步时 段来确定所接收到的数据,从而使得各个基站能够根据一致的同步时段来确 定所要进行调度的接收数据的边界, 即,使得所述同步时段能够用作各个基 站的一致的调度粒度, 比如 320ms , 因此很容易确定先后时间关系, 以及收 到了几个同步时段的数据,从而也就能够实现各基站之间所接收到的各个业 务的相应数据保持同步, 满足业务复用和同步的需求。 附图说明
从下面结合附图的详细描述中, 本发明的上述特征和优点将更明显, 其中:
图 1示出了 LTE中网络的结构;
图 2是用来说明相同的数据分组从接入网关传输到不同的基站的时延 的示意图;
图 3是根据本发明的在网关和基站之间进行同步的方法的实施例一的 流程图;
图 4是根据本发明的在网关和基站之间进行同步的方法的实施例一的 示意图;
图 5是根据本发明的在网关和基站之间进行同步的方法的实施例一的 另一示意图;
图 6是根据本发明的网关的结构示意图; 以及 图 7是根据本发明的基站的结构示意图。 具体实施方式
下面参照附图对本发明的示意性实施例进行进一步详细说明。
参照图 3, 图 3是根据本发明的在网关和基站之间进行同步的方法的 实施例一的流程图。 如图 3所示, 本实施例包括- 在网关处执行以下步骤: 在步骤 S1处, 确定要发送至基站的分组所对 应的同步时段, 所述同步时段用作基站的调度粒度; 然后在步骤 S2处, 向 所述分组的报头部分中添加指示所述同步时段的信息; 随后在步骤 S3处, 将所述分组发送至对应的多个基站; 以及
在所述多个基站的每个基站处执行以下步骤: 在步骤 S4处, 在接收到 所述分组之后,根据所述分组的报头部分中的所述信息,获知所述分组所对 应的同步时段; 然后在步骤 S5处, 将所述分组存储在缓存器中; 随后在步 骤 S6处, 在需要进行调度时, 根据所存储的分组所对应的同步时段, 确定 在调度之前终止的同步时段; 最后在步骤 S7处, 按照预定的调度策略, 对 与所确定的同步时段相对应的分组进行调度。
本实施例一中, 通过改变调度粒度来实现各基站之间所接收到的各个 业务的相应数据保持同步。
上文所述现有技术的问题在于调度粒度太小, 比如一个数据包或一帧 (10ms) , 由于颗粒度太短就容易出现不确定性。虽然现有技术通过缓存数据 分组能够保证各基站之间的缓存队首的数据的同步,但是却不能保证各基站 之间所接收到的各个业务的相应数据保持同步。
相反地, 本实施例一中, 由于在网关侧和基站侧同时引入了同步时段 的概念,使得网关侧和基站侧能够根据一致的同步时段基准来确定所要进行 调度的接收数据的边界,以达到各个基站之间针对各业务的相应数据的调度 的同步, 从而使得所述同步时段能够用作各个基站的一致的调度粒度, 比如 320ms , 因此基站很容易确定先后时间关系, 以及收到了几个同步时段的数 据,从而既能够保证各基站之间的缓存队首的数据的同步,也能够通过仅调 度所确定的已经终止的同步时段的数据,来保证各基站之间所接收到的各个 业务的相应数据保持同步, 从而能够满足业务复用和同步的需求。 优选地, 上述实施例一中, 还可包括预先在所述网关和所述多个基站 的每个基站处分别按照同一时间基准来设置所述同步时段的序列,从而能够 使得各个基站之间的同步时段的基准保持一致。
优选地, 上述实施例一中, 向所述分组的报头部分中添加指示所述同 步时段的信息的步骤可包括- 如果所述分组是一个突发中的第一个分组, 则向所述分组的报头部分 中添加标识接收到所述分组的时间所对应的同步时段的时间戳、以及标识所 述突发中所述分组所属同步时段以及先前所有同步时段的累计计数的信息, 如果所述分组是一个突发中的后续分组, 则向所述分组的报头部分中 添加所述分组所属于的突发中的第一个分组所对应的时间戳、以及标识所述 突发中所述分组所属同步时段以及先前所有同步时段的累计计数的信息。
下面仅以示例方式给出添加所述时间戳和相应计数信息后的协议数据 单元 (PDU ) 的格式的两个示意性示例- 表 1 第一示例
Figure imgf000011_0001
上述第一示例中, 基于同步时段的粒度, 在基站与网关之间进行同步, 同一突发中的分组携带相同的时间戳。 "列表长度"字段是该突发所经历的 同步时段的数量, 也即指示了所述{字节计数, 分组计数}的列表的长度。 " {字节计数,分组计数}的列表"字段是该突发的每个同步时段的字节计数 和分组计数。 显然:
该突发 (至今) 的总字节计数 =该列表中的所有字节计数之和,
该突发 (至今) 的总分组计数 =该列表中的所有分组计数之和。
上述第一示例中的时间戳是基于同步时段的粒度的, 该同步时段是在 网关和基站之间的用户面 Ml接口上设置的, 是每个 E- MBMS所特定的。同步 时段大小的一个示例是 500ms。 一个突发可以包括一个或多个同步时段 ( SYNC period )。
表 2 第二示例
{字节计数, 分组计数, 标志位 }的
时间戳 载荷 /无载荷
列表 上述第二示例中, 使用标志位来取代第一示例中的 "列表计数"字段, 如果标志位 =1 则意味着该列表中存在下个字节计数和分组计数, 如果标志 位 =0则意味着该列表结束。
上述第一示例和第二示例仅用作示例而非限定本发明, 本领域的技术 人员应当理解,其可以根据实际应用场景的需求,来灵活设置添加所述时间 戳和相应计数信息后的协议数据单元 (PDU ) 的具体格式, 其均应在本发明 权利要求所要求保护的范围之内。
优选地, 上述实施例一中, 为了充分考虑网络的时延, 向所述分组的 报头部分中添加标识接收到所述分组的时间所对应的同步时段的时间戳的 步骤可包括:将接收到所述分组的时间与预定的时延估计量相加,根据所述 相加的结果时间确定对应的同步时段,以及向所述分组的报头部分中添加标 识所确定的同步时段的时间戳。
优选地, 上述实施例一中, 根据所述分组的报头部分中的所述信息获 知所述分组所对应的同步时段的步骤可包括:根据所述分组的报头部分中包 括的时间戳,确定所述分组所属的突发的第一个分组所对应的同步时段, 以 及根据所确定的所述第一个分组所对应的同步时段、以及所述分组的报头部 分中包括的标识所述突发所对应的同步时段的累计计数的信息,来确定所述 分组所对应的同步时段。
优选地, 上述实施例一中, 所述指示所述同步时段的信息可包括指示 所述同步时段在预先设置的所述同步时段的序列中的编号的信息。
优选地, 上述实施例一中, 所述根据所存储的分组所对应的同步时段 确定在调度之前终止的同步时段的步骤可包括:根据所存储的分组所对应的 同步时段的编号,确定在调度时刻减去预定的时延估计量的时刻之前结束的 同步时段中具有最大编号的同步时段,将所确定的同步时段及在所确定的同 步时段之前的同步时段作为所述在调度之前终止的同步时段。
下面针对上述优选实施方式进一步提供示意性示例- 如图 4所示, 如果当前的同步时段是 K-1 , 则如果突发的第一个分组 在 [Τκ-ι - Max— delay - SYNC— margin, Τκ - Max— delay - SYNC— margin] 期间到大, 则该分组将被打上时间戳 K。 其中 TV,是同步时段 K-1的开始时 间, Τκ是同步时段 K的开始时间, Max_del ay是网络的最大时延, SYNC_marg i n 是所设置的同步余量, 典型地约为 40ms。
尽管如上文所述, 一个突发中的所有分组将均被打上相同的时间戳, 但是, 例如, 基站可以根据所接收到的分组中包括的 "列表长度"字段来获 知该分组属于哪个同步时段。 例如, 如果时间戳是 K-1 , 而所接收的分组中 的 "列表长度"字段的值为 2, 则基站可以获知该分组属于同步时段1(。
如图 4所示, 在确定了分组所属的特定同步时段之后, 基站将仅在不 早于该特定同步时段的时间 T开始来调度该分组,也即, 该同步时段指示了 用于基站处理的最早时间。
上述示例仅用作示意性目的, 而非限定本发明。
优选地, 上述实施例一中, 基站在定期调度缓存器中的数据时, 所采 用的调度时段可以与所述同步时段相一致,或者所述同步时段可以是所述调 度时段的整数倍。
例如,如图 5所示,第 1种情况示出了基站的调度时段与同步时段 K-l、 Κ、 K+l近似同步 (可能具有较小的偏移量), 这是最优的情况; 第 2种情况 示出了基站的调度时段是同步时段的非整数倍,同步时段 Κ要经历较长的延 迟,这并非最优的情况;第 3种情况示出了基站的调度时段是同步时段的非 整数倍的情况, 这也并非最优的情况。
此外, 优选地, 在上述示例中, 基站在一个调度时段内未调度完的数 据可以并入下一个调度时段中来进行调度。
优选地, 上述实施例一中, 还可包括以下步骤: 在所述网关处, 预先 配置指示允许每个突发所对应的最大同步时段数量的信息,以及根据所述信 息, 将持续时间超过所述最大同步时段数量的突发拆分为两个或更多个突 发。通过该措施能够避免分组的报头过大, 并且避免分组在基站中缓存过长 时间而造成不适当的时延。
优选地, 上述实施例一中, 还可包括以下步骤: 在所述网关处: 如果 在预定时期内未接收到要发送至所述多个基站的分组,则以构造并向所述多 个基站发送不包括有效载荷的假分组,在所述多个基站的每个基站处,在接 收到分组后,根据分组中包括的时间戳来确定先前接收的突发的结束。通过 该措施能够在无后续分组或者丢包时,通过由网关向基站发送假分组来向基 站指示先前突发的结束。 根据本发明的另一方面, 还提供了一种网关, 图 6是根据本发明的网 关的实施例一的结构示意图, 如图 6所示, 本实施例包括: 接收装置 61, 用于接收要发送至基站的分组; 处理装置 62, 用于确定所述接收装置 61接 收的分组所对应的同步时段,并向所述分组的报头部分中添加指示所述同步 时段的信息, 所述同步时段用作基站的调度粒度; 以及发送装置 63, 用于 向多个基站发送所述处理装置处理后的分组。
优选地, 上述实施例中, 还可包括: 设置装置, 用于预先按照与所述 多个基站相同的时间基准来设置所述同步时段的序列。
优选地, 上述实施例中, 所述处理装置可向所述分组的报头部分中添 加所述分组所属于的突发中的第一个分组所对应的时间戳、以及标识所述突 发中所述分组所属同步时段以及属于所述突发的先前所有同步时段的累计 计数的信息,其中所述时间戳指示了接收到所述第一个分组的时间所对应的 同步时段。
优选地, 上述实施例中, 还可包括: 拆分装置, 用于根据预先配置的 指示允许每个突发所对应的最大同步时段数量的信息, 对所述接收装置 61 接收到的、 持续时间超过所述最大同步时段数量的突发进行拆分。
优选地, 上述实施例中, 还可包括: 假分组发送装置, 用于如果在预 定时期内未接收到要发送至所述多个基站的分组,则以构造并向所述多个基 站发送不包括有效载荷的假分组。
上述根据本发明的网关的实施例一中, 通过改变调度粒度来实现各基 站之间所接收到的各个业务的相应数据保持同步。上文所述现有技术的问题 在于调度粒度太小, 比如一个数据包或一帧(10ms) , 由于颗粒度太短就容易 出现不确定性。根据上述本发明的网关的实施例一, 由于在网关侧和基站侧 同时引入了同步时段的概念,使得网关侧和基站侧能够根据一致的同步时段 来确定所要进行调度的接收数据的边界,从而使得所述同步时段能够在基站 的后续处理中用作基站的调度粒度, 比如 320ms, 因此基站很容易确定先后 时间关系, 以及收到了几个同步时段的数据, 从而也就能够实现各基站之间 所接收到的各个业务的相应数据保持同步, 满足业务复用和同步的需求。
根据本发明的另一方面, 还提供了一种基站, 图 7是根据本发明的基站 的实施例一的结构示意图, 如图 7所示, 本实施例包括: 缓存器 71, 用于存 储分组; 接收装置 72, 用于接收来自网关的分组; 处理装置 73, 用于根据所 述接收装置 72所接收的分组的报头部分中的所述信息,来获知所述分组所对 应的同步时段, 并将所述分组存储在所述缓存器 71中; 以及调度装置 74, 用 于在需要进行调度时, 根据所述缓存器 71中存储的分组所对应的同步时段, 来确定在调度之前终止的同步时段, 并按照预定的调度策略,对与所确定的 同步时段相对应的分组进行调度和发送。
优选地, 上述实施例中, 还可包括: 设置装置, 用于预先按照与所述 网关相同的时间基准来设置所述同步时段的序列。
优选地, 上述实施例中, 所述处理装置可根据所述分组的报头部分中 包括的时间戳, 确定所述分组所属的突发的第一个分组所对应的同步时段, 并根据所确定的所述第一个分组所对应的同步时段、以及所述分组的报头部 分中包括的标识所述突发中所述分组所属同步时段以及先前所有同步时段 的累计计数的信息, 来确定所述分组所对应的同步时段。
优选地, 上述实施例中, 所述调度装置可根据所存储的分组所对应的 同步时段的编号,确定在调度时刻减去预定的时延估计量的时刻之前结束的 同步时段中具有最大编号的同步时段,并将所确定的同步时段及在所确定的 同步时段之前的同步时段作为所述在调度之前终止的同步时段。
优选地, 上述实施例中, 所述调度装置可在调度新的突发的分组之前, 清空所述缓存器中存储的先前的突发的所有数据。
上述根据本发明的基站的实施例一中, 通过改变调度粒度来实现各基 站之间所接收到的各个业务的相应数据保持同步。上文所述现有技术的问题 在于调度粒度太小, 比如一个数据包或一帧(10ms), 由于颗粒度太短就容易 出现不确定性。根据上述本发明的基站的实施例一, 由于在网关侧和基站侧 同时引入了同步时段的概念,使得网关侧和基站侧能够根据一致的同步时段 来确定所要进行调度的接收数据的边界,以达到各个基站之间针对各业务的 相应数据的调度的同步,从而使得所述同步时段能够用作各个基站的一致的 调度粒度,从而也就能够实现各基站之间所接收到的各个业务的相应数据保 持同步, 满足业务复用和同步的需求。

Claims

权利要求
1. 一种在接入网关和基站之间进行同步的方法, 包括步骤: 在网关处,
确定要发送至基站的分组所对应的同步时段, 所述同步时段用作 基站的调度粒度,
向所述分组的报头部分中添加指示所述同步时段的信息, 将所述分组发送至对应的多个基站; 以及
在所述多个基站的每个基站处,
在接收到所述分组之后,根据所述分组的报头部分中的所述信息, 获知所述分组所对应的同步时段,
将所述分组存储在缓存器中, · 在需要进行调度时, 根据所存储的分组所对应的同步时段, 确定 在调度之前终止的同步时段,
按照预定的调度策略, 对与所确定的同步时段相对应的分组进行 调度。
2. 如权利要求 1所述的方法, 还包括步骤:
预先在所述网关和所述多个基站的每个基站处分别按照同一时间基准 来设置所述同步时段的序列。
3. 如权利要求 1所述的方法, 其中, 向所述分组的报头部分中添加指 示所述同步时段的信息的步骤包括:
如果所述分组是一个突发中的第一个分组, 则向所述分组的报头部分 中添加标识接收到所述分组的时间所对应的同步时段的时间戳、以及标识所 述突发中所述分组所属同步时段以及所述突发中的先前所有同步时段的累 计计数的信息,
如果所述分组是一个突发中的后续分组, 则向所述分组的报头部分中 添加所述分组所属于的突发中的第一个分组所对应的时间戳、以及标识所述 突发中所述分组所属同步时段以及所述突发中的先前所有同步时段的累计 计数的信息。
4. 如权利要求 3所述的方法, 其中, 所述向所述分组的报头部分中添 加标识接收到所述分组的时间所对应的同步时段的时间戳的步骤包括: 将接收到所述分组的时间与预定的时延估计量相加,
根据所述相加的结果时间确定对应的同步时段, 以及
向所述分组的报头部分中添加标识所确定的同步时段的时间戳。
5. 如权利要求 3所述的方法, 其中, 所述根据所述分组的报头部分中 的所述信息获知所述分组所对应的同步时段的步骤包括:
根据所述分组的报头部分中包括的时间戳, 确定所述分组所属的突发 的第一个分组所对应的同步时段, 以及
根据所确定的所述第一个分组所对应的同步时段、 以及所述分组的报 头部分中包括的标识所述突发所对应的同步时段的累计计数的信息,来确定 所述分组所对应的同步时段。
6. 如权利要求 2所述的方法, 其中, 所述指示所述同步时段的信息包 括指示所述同步时段在预先设置的所述同步时段的序列中的编号的信息。
7. 如权利要求 6所述的方法, 其中, 所述根据所存储的分组所对应的 同步时段确定在调度之前终止的同步时段的步骤包括:
根据所存储的分组所对应的同步时段的编号, 确定在调度时刻减去预 定的时延估计量的时刻之前结束的同步时段中具有最大编号的同步时段,将 所确定的同步时段及在所确定的同步时段之前的同步时段作为所述在调度 之前终止的同步时段。
8. 如权利要求 1-7任一所述的方法, 还包括步骤:
在所述网关处,
预先配置指示允许每个突发所对应的最大同步时段数量的信息, 以及
根据所述信息, 将持续时间超过所述最大同步时段数量的突发拆 分为两个或更多个突发。
9. 如权利要求 1-7任一所述的方法, 还包括步骤- 在所述网关处:
如果在预定时期内未接收到要发送至所述多个基站的分组, 则以 构造并向所述多个基站发送不包括有效载荷的假分组,
在所述多个基站的每个基站处, 在接收到分组后, 根据分组中包括的时间戳来确定先前接收的突 发的结束。
10. 一种网关, 包括:
接收装置, 用于接收要发送至基站的分组;
处理装置, 用于确定所述接收装置接收的分组所对应的同步时段, 并 向所述分组的报头部分中添加指示所述同步时段的信息,所述同步时段用作 基站的调度粒度; 以及
发送装置, 用于向多个基站发送所述处理装置处理后的分组。
11. 如权利要求 10所述的网关, 还包括: 设置装置, 用于预先按照与 所述多个基站相同的时间基准来设置所述同步时段的序列。
12. 如权利要求 10所述的网关, 其中, 所述处理装置向所述分组的报 头部分中添加所述分组所属于的突发中的第一个分组所对应的时间戳、以及 标识所述突发中所述分组所属同步时段以及所述突发中的先前所有同步时 段的累计计数的信息,其中所述时间戳指示了接收到所述第一个分组的时间 所对应的同步时段。
13. 如权利要求 10所述的网关, 还包括拆分装置, 用于根据预先配置 的指示允许每个突发所对应的最大同步时段数量的信息,对所述接收装置接 收到的、 持续时间超过所述最大同步时段数量的突发进行拆分。
14. 如权利要求 10所述的网关, 还包括假分组发送装置, 用于如果在 预定时期内未接收到要发送至所述多个基站的分组,则以构造并向所述多个 基站发送不包括有效载荷的假分组。
15. 一种基站, 包括:
缓存器, 用于存储分组;
接收装置, 用于接收来自网关的分组;
处理装置, 用于根据所述接收装置所接收的分组的报头部分中的所述 信息,来获知所述分组所对应的同步时段, 并将所述分组存储在所述缓存器 中; 以及
调度装置, 用于在需要进行调度时, 根据所述缓存器中存储的分组所 对应的同步时段,来确定在调度之前终止的同步时段, 并按照预定的调度策 略, 对与所确定的同步时段相对应的分组进行调度和发送。
16. 如权利要求 15所述的基站, 还包括设置装置, 用于预先按照与所 述网关相同的时间基准来设置所述同步时段的序列。
17. 如权利要求 15所述的基站, 其中所述处理装置根据所述分组的报 头部分中包括的时间戳,确定所述分组所属的突发的第一个分组所对应的同 步时段, 并根据所确定的所述第一个分组所对应的同步时段、 以及所述分组 的报头部分中包括的标识所述突发中所述分组所属同步时段以及所述突发 中的先前所有同步时段的累计计数的信息,来确定所述分组所对应的同步时 段。
18. 如权利要求 15所述的基站, 其中所述调度装置根据所存储的分组 所对应的同步时段的编号,确定在调度时刻减去预定的时延估计量的时刻之 前结束的同步时段中具有最大编号的同步时段,并将所确定的同步时段及在 所确定的同步时段之前的同步时段作为所述在调度之前终止的同步时段。
19. 如权利要求 15所述的基站, 其中所述调度装置在调度新的突发的 分组之前, 清空所述缓存器中存储的先前的突发的未发送的所有数据。
PCT/CN2008/000641 2008-03-31 2008-03-31 在网关和基站之间进行同步的方法及相应的网关和基站 WO2009121204A1 (zh)

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US12/935,834 US8493915B2 (en) 2008-03-31 2008-03-31 Method for synchronizing between a gateway and base stations and corresponding gateway and base stations
JP2011502207A JP5225457B2 (ja) 2008-03-31 2008-03-31 1つのゲートウェイと複数の基地局との間の同期を行うための方法、並びに対応するゲートウェイおよび基地局
CN200880128310.4A CN101981874B (zh) 2008-03-31 2008-03-31 在网关和基站之间进行同步的方法及相应的基站
EP08715073.6A EP2262182B1 (en) 2008-03-31 2008-03-31 Method for synchronizing a gateway and base stations and the corresponding gateway and base station
KR1020107024216A KR101445115B1 (ko) 2008-03-31 2008-03-31 게이트웨이 및 기지국들 사이를 동기화하는 방법 및 대응하는 게이트웨이와 기지국

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JP5225457B2 (ja) 2013-07-03
CN101981874B (zh) 2015-10-21
JP2011517196A (ja) 2011-05-26
US8493915B2 (en) 2013-07-23
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