WO2011160579A1

WO2011160579A1 - Random access method and system for realizing random access

Info

Publication number: WO2011160579A1
Application number: PCT/CN2011/076042
Authority: WO
Inventors: 李兰兰; 戴谦; 艾建勋
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-06-21
Filing date: 2011-06-21
Publication date: 2011-12-29
Also published as: CN102291846B; CN102291846A

Abstract

The technical problem to be resolved by the present invention is to provide a random access method and a system for realizing random access, in order to realize the return of a dedicated back-off time, which is different from the one of a Human to Human (H2H) terminal, for a Machine Type Communication (MTC) equipment. Said method includes the following steps: a base station transmits a random access response media access control layer packet data unit to a Machine type communication Equipment (ME), a back-off sub-header of said random access response media access control layer packet data unit includes the dedicated back-off time which is used when said ME reinitiates a random access. The present invention resolves the problem of network congestion, which is caused when the H2H terminal and the MTC equipment can not obtain different back-off times.

Description

一种随机接入方法及实现随机接入的*** Random access method and system for implementing random access

技术领域 Technical field

本发明涉及通讯技术领域，尤其涉及一种随机接入方法及实现随机接入的***。背景技术 The present invention relates to the field of communications technologies, and in particular, to a random access method and a system for implementing random access. Background technique

M2M ( Machine to Machine, 机器对机器 )是二十世纪九十年代提出的概念，是通信技术发展的重要驱动力量。简单的说， M2M就是机器的互联网，实现手段包括各种联网技术。 M2M技术的目标就是使所有机器设备都具备联网和通信能力，其核心理念就是网络一切（ Network Everything ) 。 M2M的通信对象为机器对机器或者人对机器。一个或多个机器之间的数据通信定义为 MTC ( Machine Type Communication, 机器类型通信），这种情况下较少需要人机互动。参与 MTC的机器，定义为 MTC设备 ( MTC UE, ME ) 。 MTC 设备是 MTC用户的终端，可通过 PLMN (公众陆地移动电话网）与其他 MTC 设备和 MTC服务器进行通信。图 1是 LTE (长期演进）架构下的 MTC网络结构，如图 1所示， MTC UE是通过运营商网络与 MTC服务器通讯的终端设备， MTC签约者是一个为 MTC终端提供业务的实体，包括多个 MTC用户。 MTC用户通过 MTC服务器和 PLMN网络相连， MTC服务器为 MTC用户提供服务。 M2M (Machine to Machine) is a concept put forward in the 1990s and an important driving force for the development of communication technology. Simply put, M2M is the machine's Internet, and the means of implementation include various networking technologies. The goal of M2M technology is to enable all machines and equipment to have networking and communication capabilities. The core concept is Network Everything. M2M's communication objects are machine-to-machine or human-to-machine. Data communication between one or more machines is defined as MTC (Machine Type Communication), in which case less human interaction is required. A machine participating in MTC, defined as an MTC device (MTC UE, ME). The MTC device is the terminal of the MTC user and can communicate with other MTC devices and MTC servers via PLMN (Public Land Mobile Network). 1 is an MTC network structure in an LTE (Long Term Evolution) architecture. As shown in FIG. 1 , an MTC UE is a terminal device that communicates with an MTC server through an operator network, and an MTC contractor is an entity that provides services for an MTC terminal, including Multiple MTC users. MTC users are connected to the PLMN network through the MTC server, which provides services to MTC users.

随机接入是无线通信***中终端的一个最基本功能，它使终端与网络建立连接成为可能。诚如其名，这种接入的发起以及釆用的资源具有随机性，接入成功也具有随机性。随机接入有两种模式：基于竟争模式和基于非竟争模式。这两种模式的随机接入过程的流程不同，适用于不同的场景。 Random access is one of the most basic functions of a terminal in a wireless communication system, which makes it possible to establish a connection between the terminal and the network. As the name suggests, the initiation of such access and the resources used are random, and the success of access is also random. There are two modes of random access: based on the competitive mode and based on the non-competitive mode. The flow of the random access process in these two modes is different and is applicable to different scenarios.

基于竟争模式的随机接入适用于： RRC— IDLE (无线链路层—空闲 )状态下的初始接入；无线链路出错以后的初始接入； RRC— CONNECTED (无线链路层—连接）状态下，上行数据传输。 The random access based on the contention mode is applicable to: RRC-IDLE (initial access in the radio link layer-idle state); initial access after the radio link error; RRC-CONNECTED (wireless link layer-connection) In the state, uplink data transmission.

基于非竟争模式的随机接入适用于： RRC— CONNECTED状态下，下行数据传输；终端在切换过程中的随机接入过程。 Random access based on non-contention mode is applicable to: RRC-CONNECTED state, downlink Data transmission; the random access procedure of the terminal during the handover process.

图 2为现有技术中，基于竟争模式的随机接入过程，包括： FIG. 2 is a random access process based on a competition mode in the prior art, including:

201 : 用户设备 ( UE ) 向演进型基站（eNB )发送随机接入前导码； 201: a user equipment (UE) sends a random access preamble to an evolved base station (eNB);

UE在发起随机接入请求之前，从可用的随机接入发送机会中随机选择一个发送机会，从可用的前导码集合中等概率地随机选择一个前导码并且将所选前导码发送到基站。 Before initiating the random access request, the UE randomly selects a transmission opportunity from the available random access transmission opportunities, randomly selects a preamble from the available preamble set, and transmits the selected preamble to the base station.

202： eNB向 UE发送随机接入应答消息； 202: The eNB sends a random access response message to the UE.

eNB在某个随机接入发送机会上正确解出一个或者多个前导码后，根据发送机会计算出对应的 RA-RNTI (随机接入 -无线网络临时标识 )。根据上述信息生成如图 3 所示的随机接入应答媒体接入层分组数据单元（RAR MAC PDU ) , 如图 3所示， MAC头中的子头和净荷中的 RAR字段是——对应的。 After the eNB correctly solves one or more preambles on a random access transmission opportunity, the eNB calculates a corresponding RA-RNTI (random access-wireless network temporary identifier) according to the transmission opportunity. According to the above information, a random access response medium access layer packet data unit (RAR MAC PDU) as shown in FIG. 3 is generated. As shown in FIG. 3, the sub-header in the MAC header and the RAR field in the payload are - corresponding of.

此外， eNB还可根据当前随机接入的负载状况来判断是否在随机接入应答 MAC PDU中添加回退（Backoff, BO )子头，回退子头中携带了回退时间。其作用是使用户在发生随机接入碰撞时并不立即在下一个可用的随机接入机会进行前导码发送，而是在经过一段退避时延后再重新发送前导码，从而降低用户之间发生碰撞的概率。 In addition, the eNB may further determine whether to add a backoff (BO) subheader in the random access response MAC PDU according to the current random access load status, and the backoff subhead carries the backoff time. The function is that the user does not immediately send the preamble to the next available random access opportunity when a random access collision occurs, but retransmits the preamble after a period of backoff delay, thereby reducing collision between users. The probability.

回退子头的结构如图 4 所示，字段 E 用来表示 BI 字段后面是否有 E-T-RAPID格式的子头，字段 T用来表示该字段后的字段里是 BI还是 RAPID, 两个字段 R表示预留的两个比特，当 H2H (人对人通信）类型 UE ( R8和 R9终端）读取到这两个预留字段时，忽略这两个字段的值， BI字段表示 UE 随机接入回退时间的选取范围。 The structure of the fallback subheader is shown in Figure 4. The field E is used to indicate whether there is a subheader in the ET-RAPID format after the BI field. The field T is used to indicate whether the field after the field is BI or RAPID, and the two fields R Indicates two bits reserved. When the H2H (person-to-person communication) type UE (R8 and R9 terminals) reads the two reserved fields, the values of the two fields are ignored, and the BI field indicates that the UE is randomly accessed. The selection range of the backoff time.

203: 终端识别， UE向 eNB发送带用户标识的 RRC消息； 203: The terminal identifies that the UE sends an RRC message with a user identifier to the eNB.

多个 UE在步骤 201若选择了相同的前导码在相同的发送机会发送，那么在步骤 202会有多个 UE收到相同的随机接入应答消息，这些 UE有相同的 C-RNTI (小区无线网络临时标识），消息 3 ( RRC消息）中包含可以唯一识别不同 UE的信息。 If multiple UEs select the same preamble to transmit in the same transmission opportunity in step 201, then multiple UEs receive the same random access response message in step 202, and these UEs have the same C-RNTI (Cell Radio) The network temporary identifier), message 3 (RRC message) contains information that can uniquely identify different UEs.

204: 竟争消除， eNB向 UE发送碰撞解决消息。 204: The contention is eliminated, and the eNB sends a collision resolution message to the UE.

由于可能有多个 UE在同一个上行授权中同时发送自己的消息 3 , eNB从中正确解调出一个消息 3 , 在 PDCCH上发送消息 4 (碰撞解决消息），对与消息 4对应的 PDCCH (物理下行控制信道）内容用消息 3 中包含的 UE的 C-RNTI进行加扰。 UE釆用自己拥有的 C-RNTI来接收 PDCCH, 如果能够正确接收 PDCCH, 则认为随机接入成功。 Since there may be multiple UEs simultaneously transmitting their own messages 3 in the same uplink grant, the eNB A message 3 is correctly demodulated, a message 4 (collision resolution message) is transmitted on the PDCCH, and the PDCCH (Physical Downlink Control Channel) content corresponding to the message 4 is scrambled with the C-RNTI of the UE included in the message 3. The UE uses its own C-RNTI to receive the PDCCH. If the PDCCH can be correctly received, the random access is considered successful.

在随机接入过程中，有两种情况可以釆用回退机制。一种是随机接入应答异常，具体来说就是如果 UE在随机接入应答中未收到其发送的 RAPID, 或者在一定时长内未收到随机接入应答。另外一种情况是如上面步骤 202所述，在 UE随机接入过程中产生碰撞，某些 UE出现随机接入失败。 In the random access process, there are two situations in which the fallback mechanism can be used. One is a random access answer exception, specifically, if the UE does not receive the RAPID it sent in the random access response, or does not receive the random access response within a certain length of time. In another case, as described in step 202 above, a collision occurs in the UE random access procedure, and some UEs have a random access failure.

此外，当基站处于过载的情况下，例如，无法再分配更多的发送消息 3 的资源等等，这时希望一些 UE能够延迟一段时间发送 RACH (随机接入）请求，可以在接收随机接入应答时，通过随机接入应答消息格式里的回退参数实现，这个回退参数就是回退机制的参数，如果监听随机接入应答消息的 UE发现有一个回退指示，那么就会将这个回退值保存起来，在随后需要重新进行随机接入时，可以随机地从 0到回退值里选取一个值作为推迟发前导码的时间。在现有技术中，回退时间参数的单位是毫秒，可以从下面 12个值中选择一个： ₀、 ₂₀、 ₃₀、 ₄₀、 60、 80、 120、 160、 240、 320、 480和 960。基站发送给终端的随机接入应答消息中携带的回退参数^^站根据负荷程度确定的，对于从一个服务小区内接入的终端都釆用同样的回退参数。 In addition, when the base station is in an overload situation, for example, it is no longer possible to allocate more resources for transmitting the message 3, etc., it is desirable that some UEs can delay the transmission of the RACH (random access) request for a period of time, and can receive the random access. When responding, it is implemented by the fallback parameter in the random access response message format. This fallback parameter is the parameter of the fallback mechanism. If the UE that listens to the random access response message finds a backoff indication, then this will be returned. The value of the return value is saved. When the random access needs to be performed again, a value can be randomly selected from 0 to the back-off value as the time for delaying the transmission of the preamble. In the prior art, the unit of the backoff time parameter is milliseconds, and one of the following 12 values can be selected: ₀ , ₂₀ , ₃₀ , ₄₀ , 60, 80, 120, 160, 240, 320, 480, and 960. The back-off parameter carried in the random access response message sent by the base station to the terminal is determined according to the load level, and the same back-off parameter is used for the terminal accessed from within one serving cell.

MTC网络中的终端数量众多，当大量终端同时发起随机接入请求接入到网络时，网络中的资源将会不足，大量 MTC设备会发生接入失败，因此会在回退时间内重新接入。在短时间内大量 MTC设备发起随机接入请求，还会造成网络的拥塞。 The number of terminals in the MTC network is large. When a large number of terminals initiate random access requests to access the network at the same time, resources in the network will be insufficient, and a large number of MTC devices will fail to access, so they will re-access during the backoff time. . A large number of MTC devices initiate random access requests in a short period of time, which also causes network congestion.

比如，电力抄表业务规定了 MTC设备在某个特定的时间向网络发送数据，需要这些 MTC设备在特定时间同时接入到网络。当大量 MTC设备同时接入到网络时，发生随机接入碰撞的概率比较大，大量的 MTC设备会出现随机接入失败，这些随机接入失败的 MTC设备还会重新接入到网络。为了緩解大量 MTC设备短时间内接入到网络对网络造成拥塞状况，需要较长的回退时间。 MTC设备在较长的回退时间内选择一个时间重新接入到网络。但是，为了不影响用户的业务质量，如果 H2H终端发生随机接入碰撞，通常需要尽快接入到网络，需要在随机接入应答中设置较短的回退时间。 For example, the power meter reading service stipulates that the MTC device sends data to the network at a specific time, and these MTC devices are required to simultaneously access the network at a specific time. When a large number of MTC devices access the network at the same time, the probability of random access collisions is relatively large. A large number of MTC devices may experience random access failures, and these random access MTC devices will re-access to the network. In order to alleviate the congestion caused by a large number of MTC devices accessing the network in a short time, a long backoff time is required. The MTC device selects a time to reconnect to the network within a longer backoff time. However, in order not to affect the user's service quality, if a random access collision occurs in the H2H terminal, it usually needs to be as soon as possible. To access the network, you need to set a shorter backoff time in the random access response.

另一方面，在某些应用场景中， MTC设备具有时间敏感性时， MTC设备具有比普通 UE高的接入优先级，此时 MTC设备要快速接入网络，需要获得比 H2H终端小的回退时间。当 H2H终端和 MTC设备在一个服务小区接入到网络时，基站不会区分终端类型进而发送差别的 RAR MAC PDIL 针对不同的终端发送的随机接入应答在同一个 RAR MAC PDU中携带的回退时间也是相同的， H2H终端和 MTC设备无法获取到不同的回退时间。因此现有技术中，无法针对 H2H终端和 MTC设备反馈不同的随机接入回退时间，从而无法解决 MTC设备在随机接入过程中造成的网络拥塞。 On the other hand, in some application scenarios, when the MTC device has time sensitivity, the MTC device has a higher access priority than the normal UE. In this case, the MTC device needs to obtain a smaller response than the H2H terminal. Retreat time. When the H2H terminal and the MTC device access the network in a serving cell, the base station does not distinguish the terminal type and then sends the difference RAR MAC PDIL. The fallback carried by the random access response sent by different terminals in the same RAR MAC PDU The time is also the same, and the H2H terminal and the MTC device cannot obtain different backoff times. Therefore, in the prior art, different random access backoff times cannot be fed back to the H2H terminal and the MTC device, so that network congestion caused by the MTC device during the random access process cannot be solved.

发明内容 Summary of the invention

本发明要解决的技术问题是提供一种随机接入方法及实现随机接入的系统，实现为 MTC设备返回不同于 H2H终端的专用回退时间。 The technical problem to be solved by the present invention is to provide a random access method and a system for implementing random access, which realizes that the MTC device returns a dedicated backoff time different from the H2H terminal.

为解决上述技术问题，本发明的一种随机接入方法，包括： To solve the above technical problem, a random access method of the present invention includes:

基站向机器类型通信设备 ( ME )发送随机接入应答媒体接入层分组数据单元，所述随机接入应答媒体接入层分组数据单元的回退子头中包括所述 ME 重新发起随机接入时釆用的专用回退时间的信息。 The base station sends a random access response medium access layer packet data unit to the machine type communication device (ME), where the backoff sub-head of the random access response medium access layer packet data unit includes the ME re-initiating random access Information on the dedicated backoff time.

优选地所述专用回退时间的信息包括： Preferably, the information of the dedicated backoff time includes:

回退子头中的回退标识字段中携带的基本回退时间；以及回退子头中的预留字段携带的调整因子的索引值。 The basic backoff time carried in the fallback identifier field in the fallback subheader; and the index value of the adjustment factor carried in the reserved field in the backoff subheader.

优选地，调整因子用于对基本回退时间的数值进行调整，以得到专用回退时间； Preferably, the adjustment factor is used to adjust the value of the basic backoff time to obtain a dedicated backoff time;

基本回退时间是人对人通信终端重新发起随机接入时釆用的回退时间。优选地，该方法还包括： The basic backoff time is the backoff time used when the person-to-person communication terminal re-initiates random access. Preferably, the method further comprises:

ME从回退标识字段中获取基本回退时间，从预留字段中获取索引值，从一预设的调整因子索引-调整因子对应关系信息中查询与索引值对应的调整因子，釆用查询到的调整因子，对基本回退时间进行数值调整，得到专用回退时间。优选地，调整因子为 ME的专用回退时间与基本回退时间之间的比例值或偏移量。 The ME obtains the basic backoff time from the rollback identifier field, obtains the index value from the reserved field, and queries the adjustment factor corresponding to the index value from a preset adjustment factor index-adjustment factor correspondence information, and uses the query to The adjustment factor is used to adjust the basic backoff time to obtain a dedicated backoff time. Preferably, the adjustment factor is a proportional value or an offset between the dedicated backoff time of the ME and the basic backoff time.

优选地， ME釆用查询到的调整因子，对基本回退时间进行数值调整的步骤包括： Preferably, the ME uses the queried adjustment factor to perform a numerical adjustment on the basic backoff time, including:

调整因子为比例值时，对基本回退时间与查询到的调整因子做乘法运算；调整因子为偏移量时，对基本回退时间与查询到的调整因子做加法运算。优选地，在回退子头中的预留字段携带调整因子的索引值的步骤包括：基站确定 ME的专用回退时间和基本回退时间 , 并确定专用回退时间与基本回退时间之间的比例值或偏移量；将比例值或偏移量作为调整因子，从调整因子索引-调整因子对应关系信息中查询调整因子的索引值，将查询到的索引值携带在回退子头的预留字段中。 When the adjustment factor is a proportional value, the basic backoff time is multiplied by the calibrated adjustment factor; when the adjustment factor is the offset, the basic backoff time is added to the queried adjustment factor. Preferably, the step of the reserved field in the back-off sub-head carrying the index value of the adjustment factor comprises: determining, by the base station, the dedicated back-off time and the basic back-off time of the ME, and determining between the dedicated back-off time and the basic back-off time The scale value or the offset value; using the scale value or the offset as the adjustment factor, querying the index value of the adjustment factor from the adjustment factor index-adjustment factor correspondence information, and carrying the queried index value in the back-off sub-header Reserved in the field.

优选地，一种随机接入方法，包括： Preferably, a random access method includes:

机器类型通信设备（ME )在重新发起随机接入时，从基站发送的随机接入应答媒体接入层分组数据单元的回退子头中获取专用回退时间的信息，根据所述专用回退时间的信息得到专用回退时间。 When the device type communication device (ME) re-initiates the random access, the information of the dedicated backoff time is obtained from the backoff sub-head of the random access response medium access layer packet data unit sent by the base station, according to the dedicated fallback The time information gets a dedicated backoff time.

所述 ME所述专用回退时间的信息得到专用回退时间的步骤包括：所述 ME从所述回退子头的回退标识字段中获取基本回退时间，从所述回退子头的预留字段中获取索引值，从一调整因子索引-调整因子对应关系信息中查询索引值对应的调整因子，釆用查询到的调整因子，对基本回退时间进行数值调整，得到专用回退时间。 The step of obtaining the dedicated backoff time by the information of the dedicated backoff time of the ME includes: obtaining, by the ME, a basic backoff time from a backoff identifier field of the backoff subheader, from the backoff subheader Obtain an index value in the reserved field, query an adjustment factor corresponding to the index value from an adjustment factor index-adjustment factor correspondence information, and use the adjusted adjustment factor to perform a numerical adjustment on the basic backoff time to obtain a dedicated backoff time. .

优选地，调整因子为专用回退时间与基本回退时间之间的比例值或偏移量； Preferably, the adjustment factor is a proportional value or an offset between the dedicated backoff time and the basic backoff time;

ME釆用查询到的调整因子，对基本回退时间进行数值调整的方法包括：调整因子若为比例值，则对基本回退时间与查询到的调整因子做乘法运算；调整因子若为偏移量，则对基本回退时间与查询到的调整因子做加法运算。 The method for adjusting the basic backoff time by the ME using the adjusted adjustment factor includes: If the adjustment factor is a proportional value, multiply the basic backoff time and the adjusted adjustment factor; if the adjustment factor is an offset The amount is added to the basic backoff time and the adjusted adjustment factor.

优选地，一种实现随机接入的***，包括：基站和机器类型通信设备 ( ME ) , 基站包含随机接入处理模块， ME包含随机接入请求模块，其中：随机接入处理模块，设置为通过随机接入应答媒体接入层分组数据单元中的回退子头，通知 ME重新发起随机接入时釆用的专用回退时间，在回退子头中的回退标识字段中携带基本回退时间，在回退子头中的预留字段携带调整因子的索引值； Preferably, a system for implementing random access includes: a base station and a machine type communication device (ME), the base station includes a random access processing module, and the ME includes a random access request module, where: The random access processing module is configured to respond to the back-off sub-header in the media access layer packet data unit by using a random access, and notify the ME to re-initiate a dedicated back-off time used for random access, in the back-off sub-header The rollback identifier field carries the basic backoff time, and the reserved field in the backoff subheader carries the index value of the adjustment factor.

随机接入请求模块，设置为在重新发起随机接入时，从随机接入应答媒预留字段中获取索引值，从一调整因子索引-调整因子对应关系信息中查询索引值对应的调整因子，釆用查询到的调整因子，对基本回退时间进行数值调整，得到专用回退时间。 The random access requesting module is configured to: when re-initiating random access, obtain an index value from a random access response media reserved field, and query an adjustment factor corresponding to the index value from an adjustment factor index-adjustment factor correspondence information,数值 Use the adjusted adjustment factor to adjust the basic backoff time to get the dedicated backoff time.

随机接入请求模块釆用查询到的调整因子，对基本回退时间进行数值调整的方法包括：调整因子若为比例值，则对基本回退时间与查询到的调整因子做乘法运算；调整因子若为偏移量，则对基本回退时间与查询到的调整因子做加法运算。 The random access request module uses the queried adjustment factor to adjust the basic backoff time by: if the adjustment factor is a proportional value, multiply the basic backoff time and the queried adjustment factor; If it is an offset, the basic backoff time is added to the queried adjustment factor.

综上所述，本发明通过随机接入应答媒体接入层分组数据单元的回退子头为 MTC设备返回不同于 H2H终端的专用回退时间，使 MTC设备和 H2H 终端可以釆用差别化的回退时间重新发起随机接入过程，解决了 H2H终端和 MTC设备无法获取到不同的回退时间，导致的网络拥塞问题。附图概述 In summary, the present invention returns a dedicated backoff time different from the H2H terminal for the MTC device by using the backoff sub-header of the random access response media access layer packet data unit, so that the MTC device and the H2H terminal can use differentiated The rollback time re-initiates the random access process, which solves the network congestion problem caused by the H2H terminal and the MTC device failing to obtain different backoff times. BRIEF abstract

图 1是现有技术中 MTC网络的架构图； 1 is an architectural diagram of an MTC network in the prior art;

图 2是现有技术中随机接入过程的流程图； 2 is a flow chart of a random access procedure in the prior art;

图 3是现有技术中 RAR MAC PDU的结构的示意图； 3 is a schematic diagram showing the structure of a RAR MAC PDU in the prior art;

图 5是本发明实施方式随机接入方法的流程图； FIG. 5 is a flowchart of a random access method according to an embodiment of the present invention; FIG.

图 7是本发明实施方式中釆用的比例值索引表；图 8是本发明实施方式中釆用的偏移量索引表； 7 is a scale value index table used in an embodiment of the present invention; 8 is an offset index table used in an embodiment of the present invention;

图 9为本发明实施方式的实现随机接入的***的架构图。本发明的较佳实施方式 FIG. 9 is a structural diagram of a system for implementing random access according to an embodiment of the present invention. Preferred embodiment of the invention

机器类型通信设备（ME ) 随机接入到网络时，如果出现网络拥塞导致 When the machine type communication device (ME) randomly accesses the network, if network congestion occurs

ME接入失败，需要 ME重新接入网络，此时 ME需要比 H2H终端（普通终端）更长的 backoff (回退）时间。而在 ME需要快速接入网络的情况下，或者 ME的接入优先级高于 H2H终端时， ME需要比 H2H终端更短的 backoff 时间。可见，实际应用中， ME需要有与 H2H终端不同的随机接入的 backoff 时间。但是，目前基站并不区分终端类型，并未给不同类型的终端以差别化的 backoff时间， H2H终端和 MTC设备无法获取到不同的 backoff时间，经常导致网络拥塞。 If the ME fails to access the network, the ME needs to re-access the network. In this case, the ME needs a longer backoff time than the H2H terminal (common terminal). When the ME needs to access the network quickly, or when the access priority of the ME is higher than that of the H2H terminal, the ME needs a shorter backoff time than the H2H terminal. It can be seen that in actual applications, the ME needs to have a different backoff time of random access than the H2H terminal. However, the current base station does not distinguish the type of the terminal, and does not provide a different backoff time for the different types of terminals. The H2H terminal and the MTC device cannot obtain different backoff times, which often leads to network congestion.

本实施方式提出利用现有的随机接入应答媒体接入层分组数据单元 ( RAR MAC PDU ) 中的回退子头，在基站在无法处理 ME发起的随机接入时，为 MTC设备反馈不同于 H2H终端的随机接入的专用回退时间。基站通过随机接入应答 MAC PDU中回退（ BO )子头中的 BI (回退标识 )字段携带一个基本 backoff时间，同时在 BO子头中的 R ( Reserved, 预留）字段中携带对基本 backoff时间的调整因子的索引值。 ME根据索引值查询到对应的调整因子后，对基本 backoff时间按照调整因子进行调整，得到 ME的专用 backoff 时间。其中，调整因子是对基本 backoff时间的数值进行调整的参数，通过调整因子对基本 backoff时间的数值进行调整，得到 ME的专用回退时间。基本 backoff时间是 H2H终端重新发起随机接入时釆用的回退时间。调整因子可以是一个比例值，此时 ME执行基本 backoff时间与调整因子的乘法操作；调整因子也可以是一个偏移量，此时 ME执行 backoff时间与偏移量的做加法操作。 The present embodiment proposes to use the backoff sub-header in the existing random access response medium access layer packet data unit (RAR MAC PDU). When the base station fails to process the random access initiated by the ME, the feedback for the MTC device is different. Dedicated backoff time for random access of H2H terminals. The base station carries a basic backoff time through the BI (Backoff Identity) field in the backoff (BO) subheader in the random access response MAC PDU, and carries the basic back in the R (Reserved) field in the BO subheader. The index value of the adjustment factor of the backoff time. After the ME queries the corresponding adjustment factor according to the index value, the ME adjusts the basic backoff time according to the adjustment factor to obtain the dedicated backoff time of the ME. The adjustment factor is a parameter for adjusting the value of the basic backoff time, and the value of the basic backoff time is adjusted by the adjustment factor to obtain a dedicated backoff time of the ME. The basic backoff time is the backoff time used by the H2H terminal to re-initiate random access. The adjustment factor can be a proportional value. At this time, the ME performs a multiplication operation of the basic backoff time and the adjustment factor; the adjustment factor can also be an offset, and the ME performs the addition operation of the backoff time and the offset.

B0子头中的 R字段为预留字段，一个 R字段为 1比特，共预留了两个 The R field in the B0 subheader is a reserved field, and one R field is 1 bit. A total of two reserved.

R字段，索引值放置在 B0子头的两个 R字段中（参考图 4 ) , 由基站通过随机接入应答消息通知到 ME。调整因子可以有多种取值，但由于预留两比特，所以调整因子的取值无法超过四种。 The R field, the index value is placed in the two R fields of the B0 subheader (refer to FIG. 4), and the base station notifies the ME through the random access response message. The adjustment factor can have multiple values, but since two bits are reserved, the adjustment factor cannot take more than four values.

为使 ME能够根据索引值查询到对应的调整因子，可以在 ME上预先配置调整因子索引 -调整因子对应关系信息，当 ME从 RAR MAC PDU中获取到调整因子的索引值时， ME可以查询到对应的调整因子。调整因子索引 -调整因子对应关系信息也可以配置到 ME以外的其他设备上， ME获取到索引值后，从该设备上查询对应的调整因子。 In order to enable the ME to query the corresponding adjustment factor according to the index value, it can be pre-configured on the ME. The adjustment factor index-adjustment factor correspondence information is used. When the ME obtains the index value of the adjustment factor from the RAR MAC PDU, the ME can query the corresponding adjustment factor. The adjustment factor index-adjustment factor correspondence information can also be configured on other devices than the ME. After the ME obtains the index value, the corresponding adjustment factor is queried from the device.

下面结合附图对本实施方式进行说明。 The present embodiment will be described below with reference to the drawings.

本实施方式是对随机接入应答 MAC PDU的回退子头进行扩展，图 5为本实施方式的随机接入方法，包括： In this embodiment, the back-off sub-header of the random access response MAC PDU is extended. FIG. 5 is a random access method according to the embodiment, and includes:

501 : ME向基站发送随机接入请求消息； 501: The ME sends a random access request message to the base station.

ME需要接入网络时，可以釆用如竟争的随机接入方法等进行接入。 When the ME needs to access the network, it can use the random access method such as competition to access.

ME发起随机接入的触发条件有多种，如收到网络侧发送的触发消息和 ME上电触发等。 ME会从可用的随机接入发送机会中随机选择一个发送机会，在所选的发送机会上发送随机接入请求消息。 There are various triggering conditions for the ME to initiate random access, such as receiving a trigger message sent by the network side and triggering the ME power-on. The ME randomly selects a sender from among the available random access transmission opportunities, and sends a random access request message on the selected transmission opportunity.

502: 基站接收到随机接入请求消息后，根据自身的处理能力判断是否有足够的资源处理 ME发起的随机接入请求； 502: After receiving the random access request message, the base station determines, according to its processing capability, whether there are sufficient resources to process the random access request initiated by the ME.

503: 基站如果判断将出现过载状况，则釆用随机接入应答 MAC PDU的回退子头 , 通知 ME重新发起随机接入时的专用 backoff时间； 503: If the base station determines that an overload condition occurs, the base station uses the back-off sub-head of the random access response MAC PDU to notify the ME to re-initiate the dedicated backoff time when the random access is initiated;

基站需要根据本身负荷状况，确定 ME的专用 backoff时间和基本回退时间。对于所述基本回退时间，是指现有协议已经规定了的 "回退时间指示： Backoff Indicator" , 该回退时间适用于普通 UE。 ME的专用 backoff时间和基本 backoff时间可以是倍数关系，在这种情况下，将调整因子设置为一个比例值，或者， ME的专用 backoff时间和基本 backoff时间有一个差值，此时，将调整因子设置为 ME的专用 backoff时间和基本 backoff时间的偏移量。调整因子为比例值和偏移量的情况，各自分别对应一个调整因子索引-调整因子对应关系信息，索引值和调整因子具有——对应关系，基站确定比例值或偏移量后，可以从相应的调整因子索引-调整因子对应关系信息中，才艮据比例值或偏移量确定出调整因子的索引值。 The base station needs to determine the dedicated backoff time and basic backoff time of the ME according to its own load condition. For the basic backoff time, it refers to the "backoff indicator" that has been specified by the existing protocol, and the backoff time is applicable to the ordinary UE. The dedicated backoff time and the basic backoff time of the ME may be a multiple relationship. In this case, the adjustment factor is set to a proportional value, or there is a difference between the dedicated backoff time of the ME and the basic backoff time. The factor is set to the offset of the dedicated backoff time of the ME and the basic backoff time. When the adjustment factor is the proportional value and the offset, each corresponds to an adjustment factor index-adjustment factor correspondence information, and the index value and the adjustment factor have a corresponding relationship, and after the base station determines the proportional value or the offset, the corresponding In the adjustment factor index-adjustment factor correspondence information, the index value of the adjustment factor is determined according to the scale value or the offset.

基站在 backoff子头的 BI字段中携带基本 backoff时间，并对该 backoff 子头中预留的 R字段进行扩展，在预留的 R字段上设置不同于现有技术中的值。如图 4所示， backoff子头中有两个 R字段，每个 R字段 1比特，可将这两个比特位上的值设置为调整因子对应的索引值，索引值可以是 00、 10、 01 或 11 , 图 6所示为索引值为 01时，对 backoff子头的扩展。 H2H终端会忽略这两个 R字段比特位上的值，釆用 BI字段中的基本 backoff时间，重新发起随机接入。 The base station carries the basic backoff time in the BI field of the backoff subheader, and the backoff The R field reserved in the subheader is extended, and a value different from the prior art is set on the reserved R field. As shown in FIG. 4, there are two R fields in the backoff subheader, and each R field has 1 bit, and the value on the two bits can be set to an index value corresponding to the adjustment factor, and the index value can be 00, 10. 01 or 11, Figure 6 shows the extension of the backoff subheader when the index value is 01. The H2H terminal ignores the values on the two R field bits and re-initiates the random access using the basic backoff time in the BI field.

504: ME判断是否需要重新发起随机接入，如果 ME确定需要重新发起随机接入，则根据随机接入应答 MAC PDU确定重新发起随机接入的专用回退时间； 504: The ME determines whether the random access needs to be re-initiated, and if the ME determines that the random access needs to be re-initiated, determining, according to the random access response MAC PDU, a dedicated backoff time for re-initiating the random access;

ME从随机接入应答 MAC PDU中的 backoff子头的 BI字段中获取基本 backoff时间，从扩展的 R字段中获取索引值，根据索引值从本地预设的调整因子索引-调整因子对应关系信息中查询调整因子， ME对基本 backoff时间按照调整因子进行调整，得到 ME的专用 backoff时间。 The ME obtains the basic backoff time from the BI field of the backoff sub-header in the random access response MAC PDU, and obtains the index value from the extended R field, according to the index value from the locally preset adjustment factor index-adjustment factor correspondence information. Query the adjustment factor, and the ME adjusts the basic backoff time according to the adjustment factor to obtain the dedicated backoff time of the ME.

调整因子为比例值时， ME执行的调整操作是对基本 backoff时间与调整因子做乘法运算，如果基站负荷过重，需要 ME的专用 backoff时间大于 H2H 终端的 backoff时间，调整因子设置为大于 1 ; 当 ME接入优先级较高，需要比 H2H终端更快速接入时，设置调整因子小于 1 , 调整因子具体的大小由基站根据本地负荷情况确定。调整因子为偏移量时， ME执行的调整操作是对基本 backoff时间与偏移量做加法运算，如果基站负荷过重，需要 ME的专用 backoff 时间大于 H2H 终端的 backoff时间，调整因子设置为正值；当 ME接入优先级较高，需要比 H2H终端更快速地接入，调整因子设置为负值，调整因子具体的大小由基站根据本地负荷情况确定。 When the adjustment factor is a proportional value, the adjustment operation performed by the ME is to multiply the basic backoff time and the adjustment factor. If the base station is overloaded, the dedicated backoff time of the ME is required to be greater than the backoff time of the H2H terminal, and the adjustment factor is set to be greater than 1; When the ME access priority is higher and needs to be accessed faster than the H2H terminal, the adjustment factor is set to be less than 1. The specific size of the adjustment factor is determined by the base station according to the local load situation. When the adjustment factor is the offset, the adjustment operation performed by the ME is to add the basic backoff time and the offset. If the base station is overloaded, the dedicated backoff time of the ME is required to be greater than the backoff time of the H2H terminal, and the adjustment factor is set to positive. Value; When the ME access priority is higher, it needs to access faster than the H2H terminal, and the adjustment factor is set to a negative value. The specific size of the adjustment factor is determined by the base station according to the local load situation.

如图 7和图 8所示为在 ME本地预设的调整因子索引 -调整因子对应关系信息，图 7中调整因子为比例值，图 8中调整因子为偏移量。图 7和图 8中的调整因子是本实施方式中为了说明而进行的举例，具体的值可以根据不同的应用场景和具体情况进行调整。 As shown in Fig. 7 and Fig. 8, the adjustment factor index-adjustment factor correspondence information preset locally in the ME, the adjustment factor in Fig. 7 is the proportional value, and the adjustment factor in Fig. 8 is the offset. The adjustment factors in FIG. 7 and FIG. 8 are examples for the description in the present embodiment, and the specific values may be adjusted according to different application scenarios and specific situations.

以下将图 7中的对应关系称为比例值索引表，将图 8中的对应关系称为偏移量索引表， ME上可以预先配置比例值索引表和偏移量索引表中的一种，基站默认釆用比例值和偏移量中的一种方式对基本 backoff时间进行调整，比如，基站默认按照比例值的方式对基本 backoff时间进行调整，则 ME上预先配置比例值索引表。 The corresponding relationship in FIG. 7 is referred to as a proportional value index table, and the corresponding relationship in FIG. 8 is referred to as an offset index table. One of the scale value index table and the offset index table may be pre-configured on the ME. By default, the base station adjusts the basic backoff time by using one of the proportional value and the offset. For example, the base station adjusts the basic backoff time by default according to the proportional value, and the scale value index table is pre-configured on the ME.

ME上也可以同时配置两种索引表，基站通过寻呼消息或***消息通知 ME, 釆用何种方式对收到的基本 backoff时间进行调整，调整方式的指示信息作为寻呼消息或***消息的一个信元发送到 ME, ***消息可以是现有的 ***消息，或者是传送 MTC信息的专用***消息。 The ME can also be configured with two index tables at the same time. The base station notifies the ME through a paging message or a system message, and uses the method to adjust the received basic backoff time. The indication information of the adjustment mode is used as the paging message or the system message. A cell is sent to the ME, and the system message can be an existing system message or a dedicated system message that carries MTC information.

ME重新发起随机接入的情况包括： ME收到的随机接入应答消息出现异常，比如消息中没有携带 RAPID或者 ME没有收到 MAC RAR, 如果出现了一 ME与其他 ME釆用了同样的随机接入前导码的情况，会产生碰撞，使某些 ME发生随机接入失败的问题，这种情况下接入失败 ME也会重新发起随机接入过程。 The case where the ME re-initiates the random access includes: The abnormality of the random access response message received by the ME is abnormal. For example, the message does not carry the RAPID or the ME does not receive the MAC RAR. If an ME occurs and the other ME uses the same random In the case of accessing the preamble, a collision occurs, causing random access failures in some MEs. In this case, the access failure ME also re-initiates the random access procedure.

505: ME在所确定的专用 backoff 时间范围内随机选取一个时间值，延迟所选取时间值后重新发起随机接入过程。 505: The ME randomly selects a time value within the determined dedicated backoff time range, and delays the selected time value to re-initiate the random access process.

当 ME的专用 backoff时间范围大于 H2H终端釆用的基本 backoff时间时， When the dedicated backoff time range of the ME is greater than the basic backoff time used by the H2H terminal,

ME可以在基本 backoff时间和专用 backoff时间范围内随机地选取一个时间值。 The ME can randomly select a time value within the basic backoff time and the dedicated backoff time range.

图 9为本实施方式的实现随机接入的***，包括：基站和 ME, 基站包含随机接入处理模块， ME包含随机接入请求模块，其中： FIG. 9 is a system for implementing random access according to the embodiment, including: a base station and an ME, where the base station includes a random access processing module, and the ME includes a random access request module, where:

随机接入处理模块，设置为在无法处理 ME发起的随机接入时，通过 RAR MAC PDU中的回退子头，通知 ME重新发起随机接入时釆用的专用回退时间，在回退子头中的 BI字段中携带基本回退时间，扩展回退子头中的 R字段携带调整因子的索引值； The random access processing module is configured to notify the ME to re-initiate the dedicated backoff time used for random access through the backoff sub-header in the RAR MAC PDU when the random access initiated by the ME cannot be processed, in the backoff The BI field in the header carries the basic backoff time, and the R field in the extended backoff subheader carries the index value of the adjustment factor;

随机接入请求模块，设置为在重新发起随机接入时，从 RAR MAC PDU 的回退子头的 BI字段中获取基本回退时间，从 R字段中获取索引值，从一调整因子索引-调整因子对应关系信息中查询索引值对应的调整因子，釆用查询到的调整因子，对基本回退时间进行数值调整，得到专用回退时间。调整因子为专用回退时间与基本回退时间之间的比例值或偏移量；随机接入请求模块釆用查询到的调整因子，对基本回退时间进行数值调整的方法包括：调整因子若为比例值，则对基本回退时间与查询到的调整因子做乘法运算；调整因子若为偏移量，则对基本回退时间与查询到的调整因子做加法运算。 The random access requesting module is configured to obtain a basic backoff time from the BI field of the backoff subheader of the RAR MAC PDU when re-initiating the random access, obtain an index value from the R field, and adjust from an adjustment factor index The adjustment factor corresponding to the query index value in the factor correspondence information is used to adjust the basic backoff time by using the adjusted adjustment factor to obtain a dedicated backoff time. Adjustment factor The sub-proportion value or offset between the dedicated back-off time and the basic back-off time; the random access request module uses the queried adjustment factor to adjust the basic back-off time by: For the proportional value, the basic backoff time is multiplied by the calibrated adjustment factor; if the adjustment factor is the offset, the basic backoff time is added to the queried adjustment factor.

上述***中的功能模块的其他功能请参考方法内容的描述。 For other functions of the function modules in the above system, please refer to the description of the method content.

本领域普通技术人员可以理解上述方法中的全部或部分步骤可通过程序来指令相关硬件完成，程序可以存储于计算机可读存储介质中，如只读存储器、磁盘或光盘等。可选地，上述实施例的全部或部分步骤也可以使用一个或多个集成电路来实现。相应地，上述实施例中的各模块 /单元可以釆用硬件的形式实现，也可以釆用软件功能模块的形式实现。本发明不限制于任何特定形式的硬件和软件的结合。 One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct the associated hardware. The program may be stored in a computer readable storage medium such as a read only memory, a magnetic disk or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific combination of hardware and software.

以上所述仅为本发明的优选实施例而已，并不用于限制本发明，对于本领域的技术人员来说，本发明可以有各种更改和变化。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。 The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

工业实用性本发明提供一种随机接入方法及实现随机接入的***，实现为 MTC设备返回不同于 H2H终端的专用回退时间。所述方法和***通过随机接入应答媒体接入层分组数据单元的回退子头为 MTC设备返回不同于 H2H终端的专用回退时间，使 MTC设备和 H2H终端可以釆用差别化的回退时间重新发起随机接入过程，解决了 H2H终端和 MTC设备无法获取到不同的回退时间，导致的网络拥塞问题。 Industrial Applicability The present invention provides a random access method and a system for implementing random access, which realizes that the MTC device returns a dedicated backoff time different from the H2H terminal. The method and system return a dedicated backoff time different from the H2H terminal to the MTC device by using the backoff sub-header of the random access response media access layer packet data unit, so that the MTC device and the H2H terminal can use the differentiated fallback The time re-initiation of the random access procedure solves the network congestion problem caused by the H2H terminal and the MTC device failing to obtain different backoff times.

Claims

权利要求书 Claim

1、一种随机接入方法，包括： 1. A random access method, comprising:

2、如权利要求 1所述的方法，其中， 2. The method of claim 1 wherein

所述专用回退时间的信息包括：所述回退子头中的回退标识字段中携带的基本回退时间；以及所述回退子头中的预留字段携带的调整因子的索引值。 The information of the dedicated backoff time includes: a basic backoff time carried in the backoff identifier field in the backoff subheader; and an index value of the adjustment factor carried in the reserved field in the backoff subheader.

3、如权利要求 2所述的方法，其中： 3. The method of claim 2, wherein:

所述调整因子是用于对所述基本回退时间的数值进行调整，以得到所述专用回退时间； The adjustment factor is used to adjust the value of the basic backoff time to obtain the dedicated backoff time;

所述基本回退时间是人对人通信终端重新发起随机接入时釆用的回退时间。 The basic backoff time is a backoff time used when a person-to-person communication terminal re-initiates random access.

4、如权利要求 2或 3所述的方法，其还包括： 4. The method of claim 2 or 3, further comprising:

所述 ME从所述回退标识字段中获取所述基本回退时间，从所述预留字段中获取所述索引值，从一预设的调整因子索引-调整因子对应关系信息中查询与所述索引值对应的调整因子，釆用查询到的调整因子，对所述基本回退时间进行数值调整，得到所述专用回退时间。 Obtaining, by the ME, the basic backoff time from the backoff identifier field, obtaining the index value from the reserved field, and querying from a preset adjustment factor index-adjustment factor correspondence relationship information The adjustment factor corresponding to the index value is used to adjust the basic backoff time by using the adjusted adjustment factor to obtain the dedicated backoff time.

5、如权利要求 4所述的方法，其中： 5. The method of claim 4, wherein:

所述调整因子为所述 ME的专用回退时间与所述基本回退时间之间的比例值或偏移量。 The adjustment factor is a ratio or offset between the dedicated backoff time of the ME and the basic backoff time.

6、如权利要求 5所述的方法，其中，所述 ME釆用查询到的调整因子，对所述基本回退时间进行数值调整的步骤包括： The method according to claim 5, wherein the step of performing the value adjustment on the basic backoff time by using the queried adjustment factor by the ME:

所述调整因子为所述比例值时，对所述基本回退时间与所述查询到的调整因子做乘法运算；所述调整因子为所述偏移量时，对所述基本回退时间与所述查询到的调整因子做加法运算。 When the adjustment factor is the ratio value, multiplying the basic backoff time and the queryed adjustment factor; When the adjustment factor is the offset, the basic backoff time is added to the queryed adjustment factor.

7、如权利要求 5所述的方法，其中，所述在所述回退子头中的预留字段携带调整因子的索引值的步骤包括： 7. The method according to claim 5, wherein the step of the reserved field in the back-off sub-head carrying an index value of the adjustment factor comprises:

所述基站确定所述 ME的专用回退时间和所述基本回退时间，并确定所述专用回退时间与基本回退时间之间的比例值或偏移量； Determining, by the base station, a dedicated backoff time of the ME and the basic backoff time, and determining a ratio or offset between the dedicated backoff time and a basic backoff time;

将所述比例值或偏移量作为所述调整因子，从所述调整因子索引-调整因子对应关系信息中查询所述调整因子的索引值，将查询到的索引值携带在所述回退子头的预留字段中。 Using the scale value or the offset as the adjustment factor, querying the index value of the adjustment factor from the adjustment factor index-adjustment factor correspondence information, and carrying the queried index value in the backoff In the reserved field of the header.

8、一种随机接入方法，包括： 8. A random access method, comprising:

9、如权利要求 8所述的方法，其中， 9. The method of claim 8 wherein

所述 ME所述专用回退时间的信息得到专用回退时间的步骤包括：所述 The step of obtaining, by the ME, the dedicated backoff time information, the dedicated backoff time includes:

ME从所述回退子头的回退标识字段中获取基本回退时间，从所述回退子头的预留字段中获取索引值，从一调整因子索引-调整因子对应关系信息中查询所述索引值对应的调整因子，釆用查询到的调整因子，对所述基本回退时间进行数值调整，得到所述专用回退时间。 The ME obtains a basic backoff time from the backoff identifier field of the backoff subheader, obtains an index value from the reserved field of the backoff subheader, and queries the information from an adjustment factor index-adjustment factor correspondence relationship information. The adjustment factor corresponding to the index value is used to adjust the basic backoff time by using the adjusted adjustment factor to obtain the dedicated backoff time.

10、如权利要求 8所述的方法，其中： 10. The method of claim 8 wherein:

所述 ME釆用查询到的调整因子，对所述基本回退时间进行数值调整的步骤包括： The ME uses the queried adjustment factor, and the step of performing numerical adjustment on the basic backoff time includes:

将所述调整因子作为所述专用回退时间与所述基本回退时间之间的比例值或偏移量； Using the adjustment factor as a ratio or offset between the dedicated backoff time and the basic backoff time;

所述调整因子若为所述比例值，则对所述基本回退时间与所述查询到的调整因子做乘法运算；所述调整因子若为所述偏移量，则对所述基本回退时间与所述查询到的调整因子 #丈加法运算。 If the adjustment factor is the ratio value, multiply the basic backoff time and the queried adjustment factor; if the adjustment factor is the offset, the basic backoff Time The adjustment factor between the query and the query is added.

11、一种实现随机接入的***，包括基站和机器类型通信设备（ME ) , 所述基站包含随机接入处理模块，所述 ME包含随机接入请求模块，其中：所述随机接入处理模块设置为：通过随机接入应答媒体接入层分组数据单元中的回退子头，通知所述 ME重新发起随机接入时釆用的专用回退时间，在所述回退子头中的回退标识字段中携带基本回退时间，在所述回退子头中的预留字段携带调整因子的索引值； A system for implementing random access, comprising a base station and a machine type communication device (ME), the base station includes a random access processing module, and the ME includes a random access request module, where: the random access processing The module is configured to: notify, by using a random access, a backoff sub-header in the media access layer packet data unit, to notify the ME to re-initiate a dedicated backoff time used for random access, in the back-off sub-header The fallback identifier field carries a basic backoff time, and the reserved field in the backoff subheader carries an index value of the adjustment factor;

所述随机接入请求模块设置为：在重新发起随机接入时，从所述随机接回退时间，从预留字段中获取所述索引值，从一调整因子索引-调整因子对应关系信息中查询所述索引值对应的调整因子，釆用查询到的调整因子，对所述基本回退时间进行数值调整，得到所述专用回退时间。 The random access request module is configured to: when re-initiating random access, obtain the index value from the reserved field from the random connection back-off time, from an adjustment factor index-adjustment factor correspondence information Querying an adjustment factor corresponding to the index value, and performing a value adjustment on the basic backoff time by using the queried adjustment factor to obtain the dedicated backoff time.

12、如权利要求 11所述的***，其中： 12. The system of claim 11 wherein:

所述调整因子为所述专用回退时间与所述基本回退时间之间的比例值或偏移量； The adjustment factor is a proportional value or an offset between the dedicated backoff time and the basic backoff time;

所述随机接入请求模块是设置为按以下方式釆用查询到的调整因子，对所述基本回退时间进行数值调整：所述调整因子若为所述比例值，则对所述基本回退时间与所述查询到的调整因子做乘法运算；所述调整因子若为所述偏移量，则对所述基本回退时间与所述查询到的调整因子 #丈加法运算。 The random access request module is configured to use the adjusted adjustment factor to perform the value adjustment on the basic backoff time: if the adjustment factor is the ratio value, the basic fallback is performed. The time is multiplied by the calibrated adjustment factor; if the adjustment factor is the offset, the basic backoff time is added to the queried adjustment factor #.

13、一种基站，包括随机接入处理模块，其中， 13. A base station, including a random access processing module, where

所述随机接入处理模块设置为：向机器类型通信设备（ME )发送随机接入应答媒体接入层分组数据单元，所述随机接入应答媒体接入层分组数据单元的回退子头包含所述 ME 重新发起随机接入时釆用的专用回退时间的信息。 The random access processing module is configured to: send a random access response medium access layer packet data unit to a machine type communication device (ME), where the backoff subheader of the random access response medium access layer packet data unit includes The ME re-initiates the information of the dedicated backoff time used for random access.

14、如权利要求 13所述的基站，其中， 14. The base station according to claim 13, wherein

所述随机接入处理模块是设置为：在所述回退子头中的回退标识字段中携带基本回退时间，在所述回退子头中的预留字段携带调整因子的索引值。 The random access processing module is configured to: carry a basic backoff time in the backoff identifier field in the backoff subheader, and the reserved field in the backoff subheader carries an index value of the adjustment factor.

15、如权利要求 13所述的基站，其中， 15. The base station according to claim 13, wherein

所述随机接入处理模块还设置为：预先确定所述 ME的专用回退时间。 The random access processing module is further configured to: predetermine a dedicated backoff time of the ME.

16、如权利要求 13所述的基站，其中， 16. The base station according to claim 13, wherein

所述基本回退时间为人对人通信终端重新发起随机接入时釆用的回退时间； The basic backoff time is a backoff time used when a person-to-person communication terminal re-initiates random access;

所述索引值用于在一预设的调整因子索引-调整因子对应关系信息中查询所述调整因子。 The index value is used to query the adjustment factor in a preset adjustment factor index-adjustment factor correspondence information.

17、如权利要求 16所述的基站，其中， 17. The base station according to claim 16, wherein

18、一种机器类型通信设备（ME ) ，包括随机接入请求模块，其中，所述随机接入请求模块设置为：在重新发起随机接入时，从基站发送来的随机接入应答媒体接入层分组数据单元的回退子头中获取回退时间的信息，才艮据所述专用回退时间的信息得到专用回退时间。 18. A machine type communication device (ME), comprising a random access request module, wherein the random access request module is configured to: when re-initiating random access, the random access response media sent from the base station The information of the backoff time is obtained in the backoff subheader of the inbound packet data unit, and the dedicated backoff time is obtained according to the information of the dedicated backoff time.

19、如权利要求 18所述的 ME, 其中， 19. The ME of claim 18, wherein

所述随机接入请求模块是设置为：从所述回退子头的回退标识字段中获取基本回退间，从预留字段中获取索引值，从一预设的调整因子索引-调整因子对应关系信息中查询所述索引值对应的调整因子，釆用查询到的调整因子，对所基本回退间进行数值调整，得到专用回退时间。 The random access request module is configured to: obtain a basic backoff from the backoff identifier field of the backoff subheader, obtain an index value from the reserved field, and use a preset adjustment factor index-adjustment factor The corresponding relationship information is used to query the adjustment factor corresponding to the index value, and the adjusted adjustment factor is used to adjust the value of the basic backoff to obtain a dedicated backoff time.

20、如权利要求 19所述的 ME, 其中， 20. The ME of claim 19, wherein

所述随机接入请求模块是设置为按照以下方式釆用所述查询到的调整因子对所基本回退间进行数值调整： The random access request module is configured to perform value adjustment between the basic backoffs by using the adjusted adjustment factors in the following manner:

将所述调整因子作为所述 ME的专用回退时间与基本回退间的比例值或偏移量。 The adjustment factor is used as a proportional value or an offset between the dedicated backoff time of the ME and the basic backoff.

21、如权利要求 20所述的 ME, 其中， 21. The ME according to claim 20, wherein

所述随机接入请求模块是设置为按照以下方式釆用所述查询到的调整因子对所述基本回退时间进行数值调整：所述调整因子若为所述比例值，则对所述基本回退时间与所述查询到的调整因子做乘法运算；所述调整因子若为所述偏移量，则对所述基本回退时间与所述查询到的调整因子 #丈加法运算。 The random access request module is configured to perform value adjustment on the basic backoff time by using the adjusted adjustment factor in the following manner: If the adjustment factor is the ratio value, multiply the basic backoff time and the queried adjustment factor; if the adjustment factor is the offset, the basic backoff The time is compared with the adjustment factor of the query.