PCU: add test cases for EGPRS Packet Channel Request

This change introduces three similar test cases:

  - TC_egprs_pkt_chan_req_signalling,
  - TC_egprs_pkt_chan_req_one_phase,
  - TC_egprs_pkt_chan_req_two_phase,

which basically send several 11 bit RACH.ind messages to the IUT
containing different variations of EGPRS Packet Channel Request.

Depending on the establisment cause, for each RACH.ind we expect
to receive an Immediate Assignment containing an EGPRS Packet
Uplink Assignment in its Rest Octets.

All test cases make sure that Request Reference in the received
Immediate Assignment messages is set to 127 as required by 3GPP
TS 44.018 (see table 9.1.8.1, note 2b), and the Extended RA IE in
the Rest Octets matches 5 LSBs of the RA value that was sent.

Change-Id: Ib5732956ea160f93d82f06bf82bea45501f439d2
Related: OS#1548
2 files changed