User's Manual

2. System Description 2-13

Figure 2-10. Ring Configuration

SONET/SDH rings are inherently self-healing. Each ring has an active path and a standby

path. Network traffic normally uses the active path. If one section of the ring fails, the

network will switch to the standby path. Switchover occurs in seconds. There may be a

brief delay in service, but no loss of payload, thus maintaining high levels of network

availability.

The consecutive point architecture implemented in the Moseley Digital Radio family is

based on a point-to-point-to-point topology that mimics fiber rings, with broadband

wireless links replacing in-ground fiber cable. A typical consecutive point network consists

of a POP and several customer sites connected using a EVENT 5800. These units are

typically in a building in an east/west configuration. Using east/west configurations, each

unit installed at a customer site is logically connected to two other units via an over-the-

air radio frequency (RF) link to a unit at an adjacent site.

Each consecutive point network typically starts and ends at a POP. A pattern of wireless

links and in-building connections is repeated at each site until all buildings in the network

are connected in a ring as shown in the following illustration for an Ethernet network. For

2 x 1+0 and 2 x 1+1 nodes, payload and NMS connections need to be jumpered between

two EVENT 5800 units. For 1 x 2+0 nodes, there is no need for jumpers as there is a

single EVENT 5800. For SDH or SONET payloads, the configuration is similar but an

external add/drop mux is required.