Feature Description
Multimedia Broadcast/Multicast Service (MBMS) is available on a number of network elements and is variously and well described on the Internet. Before looking at the implementation of eMBMS on the Cisco MME, we start with a quick overview of the 3GPP standard concepts to confirm the MME's position.
Overview per 3GPP TS 23.246
As defined by 3GPP TS 23.246:
MBMS is a point-to-multipoint service in which data is transmitted from a single source entity to multiple recipients. Transmitting the same data to multiple recipients allows network resources to be shared.
The MBMS bearer service offers two modes: Broadcast & Multicast mode. Broadcast Mode is supported for EPS and GPRS and Multicast Mode is supported for GPRS.
Use Cases for eMBMS on the MME
Transmitting one set of data to many, many eMBMS-capable end-users has a range of possible operator use cases:
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Mobile TV
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Digital Radio
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Video Kiosk or Video on Demand
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Connected Car
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Fixed LTE Quadruple Play
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Local Information such as Coupons
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Wireless Emergency Alerts
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Stadium App
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Data Feeds & Notifications
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e-Newspapers and e-Magazines
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Firmware/OS Updates
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Pushed Video Ads
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Last Mile CDN
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Internet of Things (Smart Meters)
MME Support for MBMS
In an LTE network, the operator using a Cisco MME can provide an MBMS data service using the e-MBMS solution proposed in 3GPP TS 23.246. eMBMS in the LTE network involves the following nodes and reference points:
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Broadcast Multicast Service Centre (BM-SC) - Supports various MBMS user-service specific services such as provisioning and delivery. The BM-SC sets up the e-MBMS session, initiates delivery of the content by pulling it from the content server, uses appropriate CODEC on the content, and collects the reception receipt from the UEs for certain kinds of content.
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MBMS-GW - Creates the MBMS bearer and receives the user-plane MBMS traffic from the BM-SC. Once received, the MBMS-GW allocates a multicast transport address and performs the GTP-U encapsulation of the MBMS data.
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MME - Running the Cisco MME-eMBMS service on the MME, the MME communicates with the MBMS GW and the MCE using Sm and M3 interfaces, respectively, for all eMBMS communications and functions. MME-eMBMS facilitates sessions scheduled by the BM-SC. The MME-eMBMS service identifies service areas to be served by a particular MBMS session, so that the MME handles session start, update, and stop. The MME also handles setup and configuration requests from the MCEs.
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E-UTRAN (eNodeB/MCE) - Handles session setup and broadcasting of MBMS data on the broadcast channel on the air. The Multicell/Multicast Coordination Entity (MCE) manages the MBMS content and resources.
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M1 - Is the reference point between MBMS GW and E-UTRAN/UTRAN for MBMS data delivery. IP Multicast is used on this interface to forward data.
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M3 - Is the reference point for the control plane between MME and E-UTRAN.
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Sm - Is the reference point for the control plane between MME and MBMS-GW.
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Sn - Is the reference point between MBMS GW and SGSN (S4 based) for the control plane and for MBMS data delivery. Point-to-point mode is used on this interface to forward data.
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SGi-mb - Is the reference point between BM-SC and MBMS-GW function for MBMS data delivery.
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SGmb - Is the reference point for the control plane between BM-SC and MBMS-GW.
With MBMS functionality, the MME now supports additional interfaces :
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the Sm interface, between the MME and the MBMS-GW, receives MBMS service control messages and the IP Multicast address for MBMS data reception from the MBMS-GW. It also carries the EPS GTPv2-C messages: -
MBMS Session Start messages
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MBMS Session Update messages
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MBMS Session Stop messages
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the M3 interface provides the reference point for the control plane between the MME and the MCE (E-UTRAN). The M3 Application Protocol (M3AP) supports the functions of the M3 interface by providing: -
Support for both IPV4 and IPV6 addresses at MME endpoint.
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Session Management - This overall functionality is responsible for starting, updating, and stopping MBMS sessions via the session control signaling on the SAE bearer level.
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M3 Setup functionality for initial M3 interface setup for providing configuration information.
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Reset functionality to ensure a well-defined re-initialization on the M3 interface.
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Error Indication functionality to allow a proper error reporting.
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MCE Configuration Update function to update the application level configuration data needed for the MCE.
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Relationships
The MME-eMBMS service is not associated with the MME service or any of the other major services available on the MME, such as the SBC, SLS, or SGS services.
License Information
A valid license key for the M3 and Sm interfaces is required to enable the controlling CLI and functionality of eMBMS on the MME. Contact your Cisco Account or Support representative for information on how to obtain a license.