WO2011160547A1

WO2011160547A1 - Random access method and system

Info

Publication number: WO2011160547A1
Application number: PCT/CN2011/075489
Authority: WO
Inventors: 艾建勋; 戴谦; 张银成
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-06-21
Filing date: 2011-06-08
Publication date: 2011-12-29
Also published as: CN102291845B; CN102291845A

Abstract

The present invention discloses a random access method and system. Wherein, the random access method includes the following steps: a radio access network element uses system information or paging information to indicate the random access resources allocated for a predetermined service to a terminal of the predetermined service, wherein, the random access resources comprise a dedicated preamble in a shared Physical Random Access Channel (PRACH) and/or a dedicated PRACH, and the configuration information of the dedicated PRACH and that of the shared PRACH are indicated in different system information or paging information respectively; and the terminal of the predetermined service uses the random access resources to perform random access. With the present invention, the impact on other ordinary service terminals due to the service requirements of the predetermined service is avoided.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a random access method and system. BACKGROUND OF THE INVENTION Due to the large number of mobile terminals of the M2M (Internet of Things), the connection between the originating and the network is sudden. For example, when a region recovers from a power failure, all M2M terminals in the region will initiate a request to connect to the network to register with the network, which will result in a large number of network connection requests; or in the monitored M2M application, A massive M2M terminal sensor simultaneously triggers a response to the same event, initiating a wireless connection request almost simultaneously. In addition, when the terminal of the Multimedia Broadcast Multicast Service (MBMS) receives feedback status information, if a large number of terminals are receiving MBMS services in a cell, at a certain moment, these The terminal is triggered to initiate a wireless access request to report its service reception status. In the above application scenario, on the one hand, when a large number of bursts occur in a service, multiple terminals select the same random access preamble (preamble) to initiate a random access procedure, causing preamble collisions. It will further affect the random access of ordinary terminals (H2H terminals). The common user terminal (H2H terminal) shares the same Physical Random Access Channel (PRACH) resource with the M2M terminal and the terminal of the MBMS uplink feedback service, and therefore, when uplinking from multiple M2M terminals or MBMS When the terminal of the feedback service selects the same preamble to initiate the random access procedure, the random access success rate of the ordinary user terminal will decrease, thereby causing the delay of the random access to increase. On the other hand, these large bursts of random access will generate thousands of times for ordinary user terminals. Since the random access preamble is transmitted as code division multiple access, multiple terminals use the same preamble to send random access requests. When the preamble that does not conflict is generated, it generates noise interference (inter-code interference), which reduces the performance of the base station decoding preamble. In the related art, in order to solve the above problem, there are mainly two solutions. The terminal of the M2M terminal or the MBMS uplink feedback service is a dedicated preamble code, and the terminal of the M2M terminal or the MBMS uplink feedback service is dedicated. PRACH channel. The basic idea of the dedicated preamble code scheme is as follows: In the PRACH channel of the existing cell, the dedicated preamble code is allocated to the M2M or MBMS uplink service feedback. In this case, on the same time domain and frequency domain resources in the same PRACH channel, the preamble code dedicated to the M2M or MBMS service and the preamble code used by the ordinary user terminal are allocated. That is, the common user terminal shares the time domain and the frequency domain with the M2M terminal or the terminal of the MBMS uplink feedback service, and is separated by the code domain. In this case, the shared PRACH channel may be referred to as a shared PRACH channel. For scenarios with small traffic and few random access requests, it is more suitable to use this scheme. However, when using this scheme (1), in order to reduce the impact on H2H terminal users, the cell is unlikely to allocate too many preambles for M2M services or MBMS uplink feedback services; (2) If M2M services or MBMS uplink feedback services occur Suddenly, a large number of M2M terminals or terminals of the MBMS uplink feedback service are crowded on the allocated dedicated preambles, resulting in a large random access collision, and thus the preamble code of the terminal of the M2M terminal or the MBMS uplink feedback service. The inter-code interference of the preamble code of the H2H terminal; (3) If the preamble allocated to the M2M service or the MBMS uplink feedback service needs to be adjusted due to the change of the M2M service traffic, the existing PRACH configuration information will be changed. This results in an update of System Message Block 2 (SIB2), which will trigger a normal user update system message. The basic idea of allocating a dedicated PRACH channel scheme is: adding a new PRACH channel resource based on the PRACH of the existing cell configuration, the PRACH channel (which may be referred to as a dedicated PRACH channel) is dedicated to the M2M or MBMS service, etc. User terminal business. This dedicated PRACH channel scheme is suitable for scenarios where traffic is relatively large and random access requests are numerous. In this scenario, the dedicated PRACH channel can provide more random access resources, and can completely avoid the random access generated by the M2M and MBMS services by completely isolating the random access of the M2M, MBMS services and common terminal services. The impact on the general terminal business and the number of 4. However, with this scheme, since the dedicated PRACH channel is not required when the M2M or MBMS traffic is small, the resource waste will be caused. For example, in the existing LTE protocol, the minimum allocated resources of the PRACH channel A PRACH Occasion is allocated for every 20 radio subframes, which occupies 6 PRBs (physical resource blocks). If the M2M service traffic is small, configuring a PRACH resource for the M2M service independently will result in wasted resources and utilization of the descended resources. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a random access method and system to solve at least one of the above problems. According to an aspect of the present invention, a random access method is provided, including: a radio access network element indicating, by using a system message or a paging message, a random access resource allocated to a predetermined service by a terminal of a predetermined service, where Random access resources include dedicated preamble codes and/or specializations in shared PRACH The PRACH is used, and the configuration information of the dedicated PRACH and the configuration information of the shared PRACH are respectively indicated in different system messages or paging messages; the terminal of the predetermined service uses the random access resource to perform random access. Before the radio access network element indicates the random access resource, the method further includes: the radio access network element allocates one of the following random access channel resources to the terminal of the predetermined service according to the traffic size of the predetermined service: dedicated PRACH, shared PRACH One or more dedicated preamble codes, dedicated PRACH, and one or more dedicated preamble codes in the shared PRACH. The radio access network element indicating the random access resource to the terminal includes: the radio access network element sends the configuration information of the dedicated PRACH to the terminal in a first system message block dedicated to the predetermined service; the radio access network element shares The configuration information of the PRACH channel is carried in the second system message block and sent to the terminal. The radio access network element indicates a dedicated preamble code in the shared PRACH channel by one of: indicating that the predetermined service uses the number of the dedicated preamble code in the shared PRACH; indicating that the predetermined service uses the dedicated preamble from the predetermined number in the shared PRACH. The number of codes; indicates the number of dedicated preamble codes in the shared PRACH used by the predetermined service and the number of the first dedicated preamble code. The random access resource includes one or more dedicated preamble codes of the shared PRACH, and each shared PRACH has a phase time domain resource and a different frequency domain resource; the terminal uses the random access resource to perform random access, including: A dedicated preamble code is randomly selected from one or more dedicated preamble codes of a plurality of shared PRACHs as random access preambles for random access. The foregoing random access resources include one or more dedicated PRACHs, and each dedicated PRACH has the same time domain resource and different frequency domain resources; the terminal uses random access resources for random access, including: the terminal is in multiple dedicated PRACH A preamble code is randomly selected from one or more preamble codes as a random access preamble for random access. The foregoing random access resource includes one or more dedicated preamble codes of one or more shared PRACHs and one or more dedicated PRACHs, and one or more shared PRACHs and one of the one or more dedicated PRACHs have the same time Domain resources and different frequency domain resources; the terminal uses random access resources for random access, including: one or more dedicated preamble codes of one or more shared PRACHs and one or more preambles of one or more dedicated PRACHs A preamble code is randomly selected in the code as a preamble of random access for random access. The foregoing random access resource includes one or more dedicated preamble codes of one or more shared PRACHs and one or more dedicated PRACHs, and one or more shared PRACHs and one of the one or more dedicated PRACHs have different times. The domain resource and the different frequency domain resources; the terminal uses the allocated random access resource for random access, including: the terminal selects the resource used for the random access from the allocated random access resources according to one of the following manners, and uses the selected resource to perform Random access: The terminal selects the PRACH type, and then selects the nearest time domain resource that matches the selected PRACH type from the random access resources, and randomly selects a preamble code from the PRACH type PRACH in the time domain resource; When the random access is initiated, the latest time domain resource is selected from the random access resources, and then a shared PRACH or a dedicated PRACH is randomly selected from the time domain resources, and then one of the preamble codes of the selected shared PRACH or the dedicated PRACH is randomly selected. Preamble code; the terminal according to the indication of the radio access network element or the agreement with the radio access network element in advance Selecting a special PRACH, and select a code from a special PRACH preamble or more randomly a preamble; terminal selects a random access resource allocation disposed nearest to the current time of the wireless sub-frame. The temporary access wireless network temporary identifier of the dedicated PRACH is different from the shared PRACH random access wireless network temporary identifier. According to another aspect of the present invention, a random access system is provided, including: a radio access network element, configured to indicate, by using a system message or a paging message, a random access resource allocated to a predetermined service by a terminal of a predetermined service. The random access resource includes a dedicated preamble code and/or a dedicated PRACH in the shared PRACH, and the configuration information of the dedicated PRACH and the configuration information of the shared PRACH are respectively indicated in different system messages or paging messages; The terminal of the service is set to use the random access resource for random access. The radio access network element is further configured to allocate, according to the traffic size of the predetermined service, a random access channel resource of one of the following: a dedicated PRACH, one or more dedicated preamble codes in the shared PRACH, and a dedicated PRACH. And sharing one or more dedicated preamble codes in the PRACH. The radio access network element is configured to indicate a dedicated preamble code in the shared PRACH channel by one of: indicating that the predetermined service uses the number of the dedicated preamble code in the shared PRACH; indicating that the predetermined service starts from the predetermined number in the shared PRACH The number of dedicated preamble codes; indicates the number of dedicated preamble codes in the shared PRACH used by the predetermined service and the number of the first dedicated preamble code. With the present invention, the random access resources allocated by the radio access network element for the predetermined service may include sharing.

A dedicated preamble code and/or a dedicated PRACH in the PRACH channel, so that the network can allocate appropriate random access resources according to the traffic of the predetermined service, and avoid random access conflicts and inter-coded thousand when the predetermined service traffic is large. 4, while improving the utilization of resources. At the same time, by indicating the two types of random access resources separately, it is possible to prevent the radio access network element from affecting the configuration of the shared PRACH channel when configuring the dedicated PRACH channel, thereby avoiding the other common service terminals due to the service demand of the predetermined service. Impact. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1 is a schematic structural diagram of a random access system according to Embodiment 1 of the present invention; FIG. 2 is a flowchart of a random access method according to Embodiment 2 of the present invention; FIG. 3 is a PRACH in an LTE system. FIG. 4 is a schematic diagram of a frequency domain resource configuration of a PRACH channel in an LTE system; FIG. 5 is a schematic diagram of a configuration of a multiple PRACH channel in an LTE TDD; FIG. 6 is a different PRACH channel according to Embodiment 2 of the present invention; FIG. 7 is a schematic diagram of configuration of time domain resources and frequency domain resources of another different PRACH channel according to Embodiment 2 of the present invention; FIG. 8 is another schematic diagram of Embodiment 2 of the present invention; Schematic diagram of the configuration of time domain resources and frequency domain resources of different PRACH channels. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. Embodiment 1 1 is a schematic structural diagram of a random access system according to Embodiment 1 of the present invention. The system includes: a radio access network element (for example, a base station) 10 and a terminal 20 that performs services. The access network element 10 is configured to indicate, by using the system message or the paging message, the random access resource allocated to the predetermined service to the terminal 20 of the predetermined service, where the random access resource includes a dedicated preamble in the shared PRACH. a code and/or a dedicated PRACH, and the configuration information of the dedicated PRACH and the configuration information of the shared PRACH are respectively indicated in different system messages or paging messages; and the terminal 20 is configured to perform random connection by using the random access resource. In. For example, the foregoing predetermined service may be an M2M service or an MBMS service. In a practical application, the radio access network element 10 may allocate one of the following random access resources to the predetermined service according to the traffic of the predetermined service: the dedicated PRACH, the shared PRACH (may be one, or multiple) One or more dedicated preamble codes, one of the above-described dedicated PRACHs, and one or more of the above-described shared PRACHs. In the related art, one solution is that the radio access network element 10 allocates a dedicated preamble code for a predetermined service, and another solution is that the radio access network element 10 allocates a dedicated PRACH for a predetermined service, and the traffic of the former solution in the predetermined service is used. When it is very large, it will cause a large number of random access collisions and inter-code interference, which in turn leads to access delay. The latter scheme allocates a dedicated PRACH for the service, but in general, the traffic of the scheduled service is not too large. This will result in a waste of resources. In the above system provided by the embodiment of the present invention, the radio access network element 10 may allocate a part of the dedicated preamble and/or the dedicated PRACH sharing the PRACH for the predetermined service, so that the radio access network element 10 can perform the traffic according to the predetermined service. Allocating a random access resource, allocating a dedicated preamble code when the traffic of the predetermined service is small, allocating a dedicated PRACH when the traffic is large, or configuring a dedicated PRACH and a dedicated Preamble code resource in the shared PRACH channel at the same time, thereby It can reduce random access conflicts and avoid waste of resources. Moreover, by separately indicating the above two types of random access resources (ie, the shared PRACH and the dedicated PRACH), it is possible to prevent the radio access network element 10 from affecting the configuration of the shared PRACH channel when configuring the dedicated PRACH channel, thereby avoiding the scheduled service. The business needs lead to the impact on other common business terminals. Preferably, the radio access network element 10 is further configured to allocate one of the following random access channel resources to the terminal of the predetermined service according to the traffic size of the predetermined service: one or more of the foregoing dedicated PRACH and the shared PRACH. One dedicated preamble code, the above-mentioned dedicated PRACH, and one or more dedicated preamble codes in the shared PRACH. Preferably, the radio access network element 10 is arranged to indicate a dedicated preamble code in the shared PRACH channel by one of: (1) indicating that the predetermined service uses the number of the dedicated preamble code in the shared PRACH; (2) indicating the predetermined service Using the number of dedicated preamble codes starting from the predetermined number in the shared PRACH described above; (3) indicating that the predetermined service uses the number of dedicated preamble codes in the shared PRACH and the number of the first dedicated preamble code. Embodiment 2 FIG. 2 is a flowchart of a random access method according to Embodiment 2 of the present invention. The method mainly includes the following steps (Step S202 - Step S204): Step S202: The radio access network element uses system messages or paging The message indicates the random access resource allocated to the predetermined service to the terminal of the predetermined service, where the random access resource includes a dedicated preamble code and/or a dedicated PRACH in the shared PRACH, and the configuration information of the dedicated PRACH is The configuration information of the shared PRACH is respectively indicated in different system messages or paging messages. For example, the predetermined service in the embodiment of the present invention may be an M2M service or an MBMS uplink feedback service. In a practical application, the radio access network element may allocate a random access resource to the predetermined service according to the traffic of the predetermined service. Preferably, before the random access resource is indicated to the terminal, the radio access network element first serves the predetermined service. Allocate random access resources. Specifically, the radio access network element determines whether the traffic of the predetermined service is greater than a threshold, and if yes, allocates a random access resource including the dedicated PRACH for the predetermined service, and otherwise allocates one or more shared PRACHs for the predetermined service. A random access resource of one or more dedicated preamble codes. In the embodiment of the present invention, the radio access network element configures a random access resource for the service according to the traffic of the service. Preferably, the random access resource allocated by the access network element for the predetermined service may be divided into two parts: the first part is part of the random access channel shared with other services, and the second part is dedicated to the predetermined service. Random channel resources (ie, dedicated PRACH), and the second part is dynamically configured with the demand of the predetermined service, and the first part is changed as little as possible to avoid affecting other services. That is, the first part of the resource is used to meet the requirement that the predetermined service has no traffic flow burst, and the second part of the resource is used to meet the requirement of the predetermined service in the case of a sudden burst of service traffic. Preferably, the radio access network element configures the random access resource of the predetermined service in a dedicated preamble manner, that is, the radio access network element allocates one or more shares for the predetermined service. One or more dedicated preamble codes of the PRACH to meet the access requirements without bursting scheduled services. When the radio access network element detects or is instructed that the traffic of the predetermined service exceeds a threshold (ie, there are a large number of bursts), the radio access network element configures a dedicated PRACH channel resource for the service to satisfy the bursty scheduled service access. demand. In this case, the terminal performing the predetermined service may perform random access using a dedicated preamble and/or a dedicated PRACH channel resource. In the embodiment of the present invention, after the radio access network element allocates the random access resource for the foregoing service, the configuration of the random access resource by the terminal is indicated by the system message or the paging message, preferably, for the shared PRACH channel and the dedicated For the configuration information of the PRACH channel, the radio access network element respectively indicates to the terminal by using different system message blocks or paging messages. In this way, when the radio access network element configures the dedicated PRACH resource, the system message block for configuring the shared PRACH channel does not need to be changed, so that the traffic of the predetermined service can be prevented from affecting other service terminals. It should be noted that the foregoing shared PRACH channel configuration may not include information specifically indicating a dedicated preamble used by a predetermined service. That is, the shared PRACH channel configuration information and the information indicating the preamble code dedicated to the predetermined service may be carried in different system message blocks or indicated by a paging message. Preferably, the configuration information of the dedicated PRACH channel can be carried in the service-specific system message block (SIB-x). The configuration information of the dedicated PRACH channel includes, but is not limited to, time domain resource information of the PRACH channel, frequency domain resource information, and/or preamble code configuration information of the PRACH information. FIG. 3 is a schematic diagram of PRACH time domain resource configuration. As shown in FIG. 3, the radio access network element may be configured.

One or more radio subframes are placed in the 10 or 20 radio subframes to carry the PRACH channel, and the specific radio subframe position is determined. 4 is a schematic diagram of a PRACH frequency or configuration. As shown in FIG. 4, a frequency domain position of a PRACH channel in a radio subframe is determined by configuring a PRACH frequency domain offset (Freq-Offset). Specifically, the offset value represents The location of the physical resource fast (PRB) of the 7-load PRACH channel. Moreover, in the LTE TDD system, multiple PRACH channels can be allocated in the same time i or resource. As shown in FIG. 5, different frequency domain resource blocks are respectively occupied, and the specific number of PRACHs is the same through the foregoing PRACH configuration. Indicated in the message. The different PRACH channels in the same time domain are marked with f_id. For example, in the LTE TDD PRACH configuration example shown in FIG. 5, the f_id of the PRACH channel 1 is 0, and the f_id of the PRACH channel 2 is 1. Preferably, the configuration information of the dedicated preamble code can be indicated by the service-specific system information block (SIB-y). In practical applications, the method for the radio access network element to indicate the dedicated preamble code includes, but is not limited to, one of the following: (1) indicating that the predetermined service uses the number of the preamble code in the shared PRACH channel.

( Index ); For example, in the LTE system, the preamble code used by the predetermined service (for example, M2M service) in the SIB-y is the preamble number of the shared PRACH channel configured in the SIB-2, which is numbered 0, 1, and 2. code. The PRACH channel configured by the SIB-2 is a random access resource shared by a terminal (for example, an M2M terminal) that performs the service and other terminals (for example, an H2H terminal).

(2) indicating that the predetermined service uses the number N of preamble codes in the shared PRACH channel, in which case the dedicated preamble code allocated by the radio access network element for the service is: starting from the preamble number agreed with the terminal N preamble codes; for example, in the LTE system, the preamble code used by the M2M service in the SIB-y is 10 preambles in the shared PRACH channel configured by the SIB-2, and the 10 preamble codes are contracted from the first one, Or the 10 preamble codes starting with the "dedicated preamble" defined in the last SIB-2.

(3) Instructing the predetermined service to use the number N of preamble codes in the shared PRACH channel and the number of the first premble, and the dedicated preamble code allocated at this time is: N preamble codes starting from the first preamble code number. For example, in the LTE system, the preamble code used for indicating the M2M service in the SIB-y is 10 preambles in the shared PRACH channel configured in the SIB-2, and the 10 peramble codes are indicated from the designated preamble in the Sib-y. Start with a preamble numbered 0. Preferably, in the foregoing dedicated preamble indication method, if the shared PRACH channel is multiple, the multiple shared PRACH channels may have the same or different dedicated preamble allocation. If the dedicated preambles allocated on the different shared PRACHs are different, the dedicated preamble allocation information on each shared PRACH is respectively indicated on the SIB-y. For example, in LTE TDD, a cell is configured with N PRACH channels, and each PRACH channel is shared by an M2M service terminal and an H2H service terminal, and each PRACH channel configuration is the same. The preamble dedicated to the M2M service only needs to indicate the public configuration of the preamble on the SIB-y. For another example, in LTE TDD, the cell is configured with N PRACH channels. Each of the PRACH channels has different M2M and H2H service sharing configurations. In SIB-2, the M2M service-specific preamble configuration of each shared PRACH channel is respectively indicated. Preferably, in the embodiment of the present invention, the radio access network element is between the multiple shared PRACH channels allocated by the service, or between multiple dedicated PRACH channels, or one or more shared PRACH channels and one or more pieces. The time domain resource and the frequency domain resource configuration relationship between the dedicated PRACH channels include one or any combination of the following: (1) The same time domain resources and different frequency domain resources are configured for different PRACH channels. Multiple pieces at this time

PRACH overlaps in the time domain, but different frequency domain resources are configured separately. In the LTE system, the time i or resource of the PRACH-1 is the first radio subframe of each radio frame, and the frequency domain resource is the frequency offset within the cell bandwidth. Move to 6 PRBs starting with 0. The time domain resource of PRACH-2 is also the first radio subframe of each radio frame, and its frequency domain resource is 6 PRBs with a frequency offset starting from 12. Thus, the time domain resources of PRACH-1 and PRACH-2 can be the same through different frequency offsets.

(2) Different PRACH channels are configured with different time domain resources, the same or different frequency domain resources. In the LTE system, the time i or resource of the PRACH-1 is the first radio subframe of each radio frame, and the frequency domain resource is the frequency offset within the cell bandwidth. Move to 6 PRBs starting with 0. The time domain resource of PRACH-2 is the fourth radio subframe of each radio frame, and its frequency domain resource is 6 PRBs whose frequency offset is 0 or 12. Thus, because PRACH-1 and PRACH-2 have different time domain resources, their frequency resources may be the same or different.

(3) Different time domain resources in different PRACH channel configuration parts, different frequency domain resources are configured on different PRACH channels, at least in part of the same time domain resources. For example, as shown in FIG. 8, in the LTE system, PRACH-1 is configured in the first radio subframe of each radio frame, and PRACH-2 is configured in the first and fourth radio subframes of each radio frame. Then, PRACH-1 and PRACH-2 overlap at the first radio subframe or resource. At the same time, PRACH-1 and PRACH-2 are respectively configured with different frequency i or resources, for example, PRACH-1 frequency domain resource allocation in the jtM column. The frequency of the PRACH-2 or the resource is placed on the six PRBs whose frequency band offset is 6 in the cell bandwidth. Preferably, in the embodiment of the present invention, in order to prevent the radio access network element from assigning a random access response receiving window (ra-ResponseWindow) corresponding to the dedicated PRACH channel to the shared PRACH channel, the random access occurs. Into the Radio Network Temporary Identity (RA-RNTI) collision, in the embodiment of the present invention, the RA-RNTI defining the dedicated PRACH channel and the RA-RNTI sharing the PRACH channel are not the same. For example, for LTE, if the access network element configures one or more dedicated PRACH channels for the service, the RA-RNTI of the dedicated PRACH channel can be obtained according to the following formula: RA-RNTI = N + t_id + 10*f_id ... (2); where t_id is the first radio subframe number of the PRACH channel (time), and f_id is the number of the PRACH on the different frequency domain resources in the same time domain in the LTE TDD. Where N is greater than or equal to 61, and different PRACH channels correspond to different Ns. Optionally, N = 61 + j * 60, where j is the number of the dedicated PRACH, and j is greater than or equal to zero. For example, in LTE FDD, two dedicated PRACH channels are configured, numbered as PRACH.

0 and PRACH 1 , the corresponding N in the RA-RNTI calculation formula of PRACH 0 is 61, and the N corresponding to the RN-RNTI calculation formula of PRACH-2 is 121. Take jt匕 class 4 dance. For example, in LTE TDD, a set of dedicated PRACH channels are configured. The time domain resources of the group of dedicated PRACH channels are the same and the frequency domain resources are different. At this time, the RA-RNTI corresponding to the group of dedicated PRACH channels is calculated by (2). And, the preferred choice of N is 61, and f_id in (2) is the number of PRACH in the set of PRACH. Step S204: The terminal of the predetermined service uses the random access resource to perform random access. In an actual application, the terminal selects a random access resource used by the terminal from the random access resources, and then performs random access using the selected random access resource. For example, in different resource configurations, a terminal of the predetermined service (e.g., an M2M terminal) may select a random access resource according to one or a combination of the following methods:

(1) The radio access network element is configured with one or more shared PRACH channels for the predetermined service, and each shared PRACH channel is configured with the same time domain resource and different frequency domain resources. Then the terminal is sharing A premable code is randomly selected from the dedicated preamble of the PRACH channel configuration as a preamble of the random access. For example, the terminal may randomly select a dedicated preamble according to one of the following methods: first randomly select a shared PRACH, and then select one of the dedicated preamble codes of the selected shared PRACH configuration as a preamble of the random access; The dedicated preamble code is used as an optional preamble set, and the terminal selects a preamble code from the set of optional preamble codes as a preamble for random access. For example, the cell is configured with three time domain resources, and the shared PRACH channels with different frequency domains are configured with the same or different number of M2M dedicated preamble codes on each PRACH channel. When the M2M terminal (ME) needs to initiate random access, it may first select one PRACH channel on its selected PRACH time domain resource, and then select one of the M2M dedicated preamble codes on the PRACH channel. Alternatively, the ME may randomly select one of all the preamble codes configured on the above three PRACH channels.

(2) The radio access network element allocates one or more dedicated PRACH channels for the predetermined service, and each dedicated PRACH channel is configured with the same time domain resource and different frequency domain resources. Then, the terminal of the predetermined service randomly selects a premable code as the preamble of the random access in the preamble code of the allocated dedicated PRACH channel configuration. For example, the randomly selected method may include, but is not limited to: 1) first randomly selecting one of the above-mentioned dedicated PRACHs, and then selecting one of the preamble codes configured as the random access preamble; 2) using the above-mentioned dedicated PRACH channels The preamble code is used as an optional preamble set, and the terminal selects a preamble code from the set of optional preamble codes as the preamble of the random access. For example, when there are three cell configurations, the i3⁄4 resources are the same, and the frequency i or different M2M service dedicated PRACH channels. The same or different number of M2M-dedicated preamble codes are configured on each PRACH channel. When the ME needs to initiate random access, it may first select a PRACH channel on its selected PRACH time domain resource, and then select one of the preamble codes on the PRACH channel. Alternatively, the ME may randomly select one of all the preamble codes configured on the above three PRACH channels.

(3) The radio access network element is configured with one or more shared PRACH channels for the predetermined service, and one or more dedicated PRACH channels are configured at the same time, and the PRACH channels are configured with the same time domain and different frequency domain resources. The terminal that performs the service is configured in the foregoing shared PRACH information configuration. A preamble code randomly selected from the preamble and the dedicated PRACH channel is used as a preamble for random access. For example, the terminal may randomly select a preamble according to the following method: first select a PRACH channel (a shared PRACH channel that can be allocated for the access network element, or a dedicated PRACH channel allocated for the access network element), and select a probability of a specific PRACH channel. It is proportional to the number of preamble codes used by the specific service configured, and then randomly selects a dedicated preamble code for the service on the selected PRACH channel. Or, all the preambles dedicated to the service configured by using the dedicated PRACH channel and the shared PRACH channel are used as an optional preamble code set, and the terminal randomly selects a preamble code from the reliable preamble code as a preamble of the random access. For example, the access network element allocates a shared PRACH channel to the terminal, and 10 preamble codes are configured for the M2M service. And another dedicated PRACH channel is allocated, and the dedicated PRACH channel is configured with 64 pre-mble codes for M2M services. When the ME initiates the random access, on the time domain resource of the PRACH channel, first select a PRACH channel, wherein the 4 rate of selecting the shared PRACH channel is 10:64 compared with the rate of selecting the dedicated PRACH channel 4. A Preamble code is then randomly selected from the selected PRACH channel. Or, the ME uses the 10 preamble codes of the shared PRACH channel and the 64 preamble codes of the dedicated PRACH channel as an optional preamble set, and randomly selects a preamble code therefrom.

(4) The radio access network element allocates one or more shared PRACH channels for the reservation, and is configured with one or more dedicated PRACH channels. Each PRACH channel is configured with different time domain and frequency domain resources. The method for the terminal to select a random channel resource includes:

1) The terminal first selects whether to use the shared PRACH resource or the dedicated PRACH resource, that is, first selects the type of the PRACH channel. After the PRACH channel type is selected, the most recent time domain resource with the selected PRACH type is selected, and then according to the configuration of the PRACH channel on the time domain resource, respectively, according to the method of (1) or (2) above. PRACH channel and preamble code. For example, the PRACH type may be selected according to the ratio of the number of resources available for the service of the different types of PRACH channels allocated, or the ratio of the different PRACHs selected by the base station to the terminal, or according to the base station. The indication or protocol stipulates a preference for a particular type of PRACH. 2) The terminal first selects the timing of initiating random access according to the principle of proximity, that is, when the terminal needs to initiate random access, selects the latest time domain resource to which the shared PRACH or the dedicated PRACH channel is allocated, and then according to the time domain resource. For the configuration of the upper PRACH channel, the PRACH channel and the Preamble code are selected according to the manner of (1) or (2) or (3) above. For example, a shared PRACH-1 channel is configured in the cell, where 10 Preamble codes are designated as M2M service terminals, and a dedicated PRACH-2 is configured, 64 preambles are configured, and the time domain resources of PRACH-1 are odd and The radio subframe 1 of the even radio frame, the time domain resource of the PRACH-2 is the radio subframe 2 of the even radio frame. Then, the preamble ratio of the PRACH-1 and PRACH-2 channels that can be used for the M2M service is 20:64 (20 preambles with 64 shared PRACHs and 64 dedicated PRACH preambles are arranged in every 2 radio frames).

The ME may prefer to select the PRACH channel type in a ratio of 20:64, that is, the 20/84 rate is selected to share the PRACH, and the 64/84 rate is selected as the dedicated channel. Then, the ME selects a radio subframe configured with a PRACH of the selected type closest to the current time, and then selects the preamble of the PRACH to initiate random access on the radio subframe. In the embodiment of the present invention, the PRACH channel type selection ratio ME may be calculated according to the PRACH channel configuration, or the base station indicates to the ME by signaling.

3) The terminal may preferentially select a dedicated PRACH channel according to the radio access network element indication or the agreement with the radio access network element in advance.

4) The terminal may initiate random access according to the most recent selection, that is, selecting the wireless subframe configured with the PRACH channel resource closest to the current time. It should be noted that, the random selection of the foregoing PRACH channel or preamble code needs to ensure that the optional PRACH or preamble code has the same selected rate. Moreover, the preamble of the foregoing PRACH channel does not include a preamble code reserved for non-contention based random access, wherein the non-contention based random access means that the base station allocates a preamble code for the terminal for random access, The preamble cannot be used by the terminal itself. In the related art, one solution is that the radio access network element allocates a dedicated preamble code for the predetermined service, and the other scheme is that the radio access network element allocates a dedicated PRACH for the predetermined service, and the former scheme has a large traffic in the predetermined service. In this case, a large number of random access collisions and inter-code interferences are caused, which in turn leads to access delay, while the latter scheme allocates a dedicated PRACH for the service, but in general, the service is scheduled. The traffic will not be too large, which will result in wasted resources. In the above method provided by the embodiment of the present invention, the random access resource allocated by the radio access network element for the predetermined service includes a part of the dedicated preamble code and/or the dedicated PRACH of the shared PRACH, so that the radio access network element can be according to the predetermined service. The traffic is allocated to the random access resource. When the traffic of the service is small, the dedicated preamble code is allocated, and when the traffic is large, the dedicated PRACH is allocated, thereby reducing random access conflicts and avoiding waste of resources. In addition, the two types of random access resources are respectively indicated, so that the radio access network element can be configured to affect the configuration of the shared PRACH channel when configuring the dedicated PRACH channel, thereby avoiding the service requirements of the predetermined service to other common service terminals. influences. In the above description, in the embodiment of the present invention, the random access resource allocated by the network radio access network element for the predetermined service may include a dedicated preamble code and/or a dedicated PRACH in the shared PRACH channel, so that the network can be scheduled according to the reservation. The traffic of the service is allocated with appropriate random access resources, which avoids random access conflicts and inter-code interference when the predetermined service traffic is large, and improves resource utilization. At the same time, by indicating the two types of random access resources separately, it is possible to prevent the radio access network element from affecting the configuration of the shared PRACH channel when configuring the dedicated PRACH channel, thereby avoiding the other common service terminals due to the service demand of the predetermined service. Impact. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above 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 scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claims A random access method, including:

The radio access network element indicates, by using a system message or a paging message, a random access resource allocated to the predetermined service to the terminal of the predetermined service, where the random access resource includes a dedicated in the shared physical random access channel PRACH. Randomly accessing a preamble preamble code and/or a dedicated PRACH, and the configuration information of the dedicated PRACH and the configuration information of the shared PRACH are respectively indicated in different system messages or paging messages;

The terminal of the predetermined service uses the random access resource to perform random access. The method according to claim 1, wherein, before the radio access network element indicates the random access resource, the method further includes:

And the radio access network element allocates one of the following random access channel resources to the terminal of the predetermined service according to the traffic size of the predetermined service: one or more of the dedicated PRACH and the shared PRACH One or more of the dedicated preamble code, the dedicated PRACH, and the dedicated preamble code. The method according to claim 1, wherein the indicating, by the radio access network element, the random access resource to the terminal comprises:

The radio access network element carries the configuration information of the dedicated PRACH in the first system message block dedicated to the predetermined service, and sends the configuration information to the terminal;

The radio access network element carries configuration information of the shared PRACH channel in a second system message block and sends the configuration information to the terminal. The method according to claim 1, wherein the radio access network element indicates the dedicated preamble code in the shared PRACH channel by one of:

Instructing the predetermined service to use a number of a dedicated preamble code in the shared PRACH;

Instructing the predetermined service to use a quantity of a dedicated preamble code starting from a predetermined number in the shared PRACH;

Instructing the predetermined service to use the number of dedicated preamble codes in the shared PRACH and the number of the first dedicated preamble code. The method according to claim 1 or 2, wherein the random access resource includes one or more of the dedicated preamble codes of the plurality of shared PRACHs, and each of the shared PRACHs has phase time domain resources. And different frequency domain resources;

The terminal performing the random access by using the random access resource includes: the terminal randomly selecting one dedicated preamble code as one of the plurality of the dedicated preamble codes of the shared PRACH as a preamble of the random access to perform randomization Access. The method according to claim 1 or 2, wherein the random access resource comprises one or more dedicated PRACHs, and each of the dedicated PRACHs has the same time domain resource and different frequency domain resources;

The terminal performing the random access by using the random access resource includes: the terminal randomly selecting one preamble code as one of the plurality of preamble codes of the dedicated PRACH as a random access preamble for random access . The method according to claim 1 or 2, wherein the random access resource comprises one or more of the dedicated preamble codes of the one or more shared PRACHs and one or more of the dedicated PRACHs, and one Or the plurality of the shared PRACHs and the one of the one or more of the dedicated PRACHs have the same time domain resource and different frequency domain resources; the terminal using the random access resource for random access includes: The terminal randomly selects one preamble code as one of the one or more of the dedicated preamble codes of the shared PRACH and one or more preamble codes of the one or more of the dedicated PRACHs as a preamble of the random access. Perform random access. The method according to claim 1 or 2, wherein the random access resource comprises one or more of the dedicated preamble codes of the one or more shared PRACHs and one or more dedicated PRACHs, and one or more The shared PRACH and each of the one or more dedicated PRACHs have different time domain resources and different frequency domain resources;

The terminal performing the random access by using the allocated random access resource includes: the terminal selecting a resource used for random access from the allocated random access resources according to one of the following manners, using the selected resource. Perform random access:

The terminal selects a PRACH type, and then selects a nearest time domain resource that matches the selected PRACH type from the random access resources, and randomly selects one of the PRACH types of PRACHs in the time domain resource. Preamble code When the terminal needs to initiate random access, the terminal selects the latest time domain resource from the random access resources, and then randomly selects one of the shared PRACH or the dedicated PRACH from the time domain resource, and then selects from the time domain resource. Randomly selecting a preamble code from the preamble code of the shared PRACH or the dedicated PRACH;

The terminal selects one of the dedicated PRACHs according to an indication of the radio access network element or an agreement with the radio access network element in advance, and randomly selects one of the one or more preamble codes of the dedicated PRACH. Preamble code

The terminal selects a wireless subframe that is configured with the allocated random access resource closest to the current time.

The method according to claim 1 or 2, wherein the random access radio network temporary identifier of the dedicated PRACH is different from the shared PRACH random access radio network temporary identifier.

10. A random access system, including:

a radio access network element, configured to indicate, by using a system message or a paging message, a random access resource allocated to the predetermined service to a terminal of a predetermined service, where the random access resource includes a dedicated preamble code in the shared PRACH And/or a dedicated PRACH, and the configuration information of the dedicated PRACH and the configuration information of the shared PRACH are respectively indicated in different system messages or paging messages;

The terminal of the predetermined service is configured to perform random access by using the random access resource.

The system according to claim 10, wherein the radio access network element is further configured to allocate one of the following random access channel resources to the terminal of the predetermined service according to the traffic size of the predetermined service: Dedicated PRACH, one or more of the dedicated preamble codes in the shared PRACH, the dedicated PRACH, and one or more of the shared preamble codes.

12. The system of claim 10, wherein the radio access network element is configured to indicate the dedicated preamble code in the shared PRACH channel by one of:

Instructing the predetermined service to use a number of dedicated preamble codes starting from a predetermined number in the shared PRACH; Instructing the predetermined service to use the number of dedicated preamble codes in the shared PRACH and the number of the first dedicated preamble code.