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MBMS logical architecture for E-UTRAN

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MBMS logical architecture for E-UTRAN

Introduction

Multimedia Broadcast Multicast Service (MBMS) is a standard used to deliver multimedia content over cellular networks. MBMS was introduced in 3GPP Release 6, and it has been improved in subsequent releases. MBMS is designed to provide efficient delivery of multimedia content to a large number of users simultaneously, such as live video streaming, software updates, or firmware updates. In this article, we will discuss the MBMS logical architecture for Evolved Universal Terrestrial Radio Access Network (E-UTRAN).

MBMS Logical Architecture

The MBMS logical architecture is based on the Broadcast/Multicast Service Centre (BM-SC) and the Multimedia Broadcast/Multicast Service Gateway (MBMS-GW). The BM-SC is responsible for managing the MBMS service, including session management, control plane signaling, and content management. The MBMS-GW is responsible for the delivery of MBMS traffic to the radio access network (RAN).

The BM-SC is a functional entity within the core network that interfaces with the E-UTRAN via the MBMS Service Data Network (MSDN) interface. The MSDN interface is used for control plane signaling between the BM-SC and the E-UTRAN, such as session management, service announcement, and content management. The BM-SC also interfaces with the MBMS-GW via the MBMS-Bearer Service Network (MBSN) interface.

The MBMS-GW is a functional entity within the RAN that interfaces with the BM-SC via the MBSN interface. The MBMS-GW is responsible for the delivery of MBMS traffic to the RAN, including the scheduling of MBMS transmissions and the delivery of MBMS traffic to the appropriate cells. The MBMS-GW also performs congestion control and admission control for MBMS traffic.

The E-UTRAN includes several functional entities that support MBMS, including the MBMS-Bearer Service (MBS), the MBMS User Service (MBMS-UE), and the MBMS Service Access Point (MBMS-SAP). The MBS is responsible for the transport of MBMS traffic over the air interface. The MBMS-UE is the mobile device that receives the MBMS traffic. The MBMS-SAP is the interface between the MBS and the MBMS-UE.

The MBMS logical architecture includes the following functional entities:

  1. BM-SC: The Broadcast/Multicast Service Centre is responsible for the management of the MBMS service, including session management, control plane signaling, and content management. The BM-SC interfaces with the E-UTRAN via the MSDN interface and with the MBMS-GW via the MBSN interface.
  2. MBMS-GW: The Multimedia Broadcast/Multicast Service Gateway is responsible for the delivery of MBMS traffic to the RAN, including the scheduling of MBMS transmissions and the delivery of MBMS traffic to the appropriate cells. The MBMS-GW also performs congestion control and admission control for MBMS traffic. The MBMS-GW interfaces with the BM-SC via the MBSN interface.
  3. MBS: The MBMS-Bearer Service is responsible for the transport of MBMS traffic over the air interface.
  4. MBMS-UE: The MBMS User Service is the mobile device that receives the MBMS traffic.
  5. MBMS-SAP: The MBMS Service Access Point is the interface between the MBS and the MBMS-UE.

MBMS Session Management

The MBMS session management is the process of establishing and terminating MBMS sessions. The session management includes the following steps:

  1. Service Announcement: The BM-SC sends a service announcement to the E-UTRAN to inform the UE about the availability of the MBMS service. The service announcement includes information about the MBMS service, such as the service ID, service type, and service area.
  2. Service Request: The UE sends a service request to the E-UTRAN to request the MBMS service. The service request includes information about the UE, such as the UE identity and capabilities.
  3. Session Setup: The E-UTRAN initiates the session setup by sending a session start request to the BM-SC. The session start request includes information about the MBMS service, such as the service ID, service type, and service area.
  4. Content Delivery: The BM-SC sends the MBMS content to the MBMS-GW for delivery to the UE. The MBMS-GW schedules the MBMS transmissions to the appropriate cells based on the UE location and cell capacity.
  5. Session Termination: The session termination is initiated by the BM-SC or the UE. The BM-SC sends a session stop request to the E-UTRAN to terminate the session. The UE can also terminate the session by sending a service stop request to the E-UTRAN.

MBMS Content Management

The MBMS content management is the process of managing the MBMS content, including the creation, storage, and distribution of MBMS content. The content management includes the following steps:

  1. Content Creation: The MBMS content is created by the content provider. The content can be in various formats, such as audio, video, or data.
  2. Content Encoding: The MBMS content is encoded to a format that is suitable for transmission over the air interface. The encoding can be done using various techniques, such as compression, encryption, or error correction.
  3. Content Storage: The encoded MBMS content is stored in the BM-SC or the MBMS-GW. The content is stored in a cache to facilitate faster delivery to the UE.
  4. Content Distribution: The MBMS content is distributed to the UE via the MBMS-GW. The MBMS-GW schedules the MBMS transmissions to the appropriate cells based on the UE location and cell capacity.

MBMS Transmission

The MBMS transmission is the process of delivering the MBMS content to the UE over the air interface. The transmission includes the following steps:

  1. Scheduling: The MBMS-GW schedules the MBMS transmissions to the appropriate cells based on the UE location and cell capacity. The scheduling is done to optimize the delivery of the MBMS content to the UE.
  2. MBMS-Bearer Service (MBS) Setup: The MBS is established between the UE and the E-UTRAN for the transmission of MBMS traffic.
  3. MBMS Traffic Delivery: The MBMS content is delivered to the UE over the MBS. The MBMS traffic is delivered in bursts to optimize the use of radio resources.
  4. MBS Release: The MBS is released after the MBMS transmission is complete. The release of the MBS frees up radio resources for other users.

Conclusion

The MBMS logical architecture for E-UTRAN is designed to provide efficient delivery of multimedia content to a large number of users simultaneously. The MBMS logical architecture includes the BM-SC, the MBMS-GW, the MBS, the MBMS-UE, and the MBMS-SAP. The MBMS session management, content management, and transmission processes are well-defined and efficient. MBMS is an important technology for delivering multimedia content over cellular networks, and it has been adopted by many network operators around the world.