The BB2x unit is a digital signal processing board, consisting of two independent baseband modules. Each module functions independently for its own TSxx unit. The BB2x unit also controls frequency hopping.
Externally all the units are alike except for the model number on the face of each. Internally, the major difference is the additional EDGE capability provided by the BB2E and BB2Funits. BB2A units can only be used with GSM (TSxA) transceiver units. The BB2E and BB2F may be used with or can replace the BB2A and supports GSM (TSxA) and GSM/EDGE (TSxB) transceiver units. EDGE operation is only possible when BB2E or BB2F units are used in conjunction with TSxB transceiver units.
The front panel of the BB2x unit is grounded to handle electrostatic discharges.
The BB2x units of Nokia UltraSite EDGE Base Station have the following main functions:
Process digital speech and data channels signals
Manage all speech function signalling
Uses software downloaded from the Base Operations and Interfaces (BOIx) unit
Sets internal timing according to clock references from the BOIx unit
Supports synthesised radio frequency (RF) and baseband (BB) frequencyhopping