Background and Scope

When a network employing SNMS modems is configured solely in a hub-spoke configuration, the management and control of network connectivity is centralized at the hub, the link layer connections are structurally well-defined, and routing for the network layer is also well-defined. Extension of the SNMS requirements standard to mesh overlay configurations requires development and definition of a broader set of procedures and protocols for connection control.

The need for a connection protocol framework specific to DVB-RCS was identified some time ago in ETSI and DVB groups, and is in the process of being prototyped in the IBIS/AmerHis network. Another similar connection protocol also was developed by a TIA member company for a processed satellite system.

The ETSI/DVB C2P [Ref. 10] addresses both regenerative and transponded (transparent) networks, and allows for multipoint/multicast connections. The SNMS is intended only for transponded use. In this document, only unicast (point-to-point) connections will be considered.

This document has been developed using inputs from both ETSI/DVB and TIA member companies . The following terminology equivalencies should be noted:

• NOCC = NCC (usually located at the hub or Gateway/GW)
• ST = RCST
• C2P = CCP = SMCP

Mesh transparent network

This network is based on an architecture that supports Hub-spoke and Peer-to-Peer communications using a transparent/transponded satellite. The Hub shall have the capability to transmit DVB/S2 and receive the return channel of DVB-RCS. Similarly, the RCSTs shall have the capability to receive the DVB/S2 signal transmitted by the Hub. In addition, some or all of the RCSTs will have an optional capability to receive DVBRCS, thus obtaining mesh connectivity. The mesh network is therefore an overlay to the star (or hub-spoke) DVB-RCS network. Having the star network as a core has some implications for the connection control protocol. In particular, many of the physical channels will typically be operating before a given mesh connection is required. Having the hub and the Network Control Center (NCC) co-located also simplifies routing and route discovery issues for the mesh network.

Optionally, the Hub/Gateway may be treated as a member of the mesh network (except that the "NCC – RCST" SMCP messages would be internal). In other words, the SMCP may be used for establishment and release of IP traffic connections between a meshenabled RCST and the Hub/Gateway. However, for backwards compatibility with nonmesh DVB-RCS RCSTs, and for initial network establishment, the access and connection protocols for DVB-RCS shall also be supported by all terminals.