|
Applications Cascading Cell Site Application Figure 3 shows the SC 553 deployed as a CSU in remote cell site locations. Two SC 553s housed in a SC 2000 enclosure, support reduced-cost fractional T1 services to cell sites with less active cellular phone service requirements. At each cell site, two ports of a base station transceiver/switch are each connected to a DSX-1 interface of a SC 553. In this application, one SC 553 functions as a recipient for assigned T1 DS0s while the other SC 553 functions as transporter of excess DS0x to adjacent cell sties. Typically, a DS0 is reserved for transporting network management commands and responses to each cell site. In this application, should cellular phone service requirements increase at any particular cell site, that site can be reconfigured with one or more full T1 circuits. The switching station is configured with a SpectraComm Shelf in support of a series of SC 553 T1 DSU/CSUs. In this example, each SC 553 at the switching station is terminated with a T1 circuit wherein each circuit support some number of cascaded remote cell sites. T1 Access and Cascading Cell Site Application The application shown in Figure 4 illustrates the use of the SC 553 as a DSU/CSU at remote cell sites with corresponding units at a designated switching station. At three cell sites of this application, a single SC 553 installed in a SpectraComm 2000 shelf at each remote cell site functions as a fractional DSU as a means of conserving line costs. The DTE interface to the base station transceiver/switch is an EIA 530/422. At the switching station, a SpectraComm Shelf is equipped with an SCM card and cascaded SC 553 units. Ports on a fast packet switch are connected via EIA 530/422 interface to SC 553 units. At the remaining three remote cell sites SC 553 units employ the optional cascade port, permitting cascading among co-connected cell sites and offering another line cost savings approach. This application can be SNMP managed from a designated location using GDC's TEAM 553 application software in conjunction with a UNIX based workstation. Telnet and MIB browsers offer less efficient management alternatives, but are supported as an alternative to TEAM software. Network management diagnostic support for this application using TEAM 553 software consists of remote optioning of the SC 553, retrieving user and network performance statistics, performing a T1 payload loopback, performing T1 channel tests without interference to other channels, monitoring SNMP alarms, and monitoring DTE EIA lead status. Network diagnostic communications to remote cell sites requires use of the facility data link in non-DACS T1 networks or a designated T1 channel DSO in either DACS or non-DACS environments.
| ||||
