Osmocom Packet control Unit (PCU): Network-side GPRS (RLC/MAC); BTS- or BSC-colocated
https://osmocom.org/projects/osmopcu
a004e6a823
The timing advance of any TBF is stored when it ends. Whenever a new TBF with the same TLLI is created (downlink TBF), the stored TA is recalled. This algorithm assumes that the mobile does not move too fast during transfer. Also the mobile must start a connection in order to get correct initial timing advance. This algorithm does not implement the timing advance procedure as defined in TS 04.60. To implement the standard timing advance procedure, the BTS must decode RACH on certain bursts, the mobile is expected to send them. This requires much more complexity to a transceiver like USRP/UmTRX or Calypso BTS. The algorithm was tested at TA >= 8 and works quite well. |
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| src | ||
| .gitignore | ||
| COPYING | ||
| Makefile.am | ||
| README | ||
| configure.ac | ||
| git-version-gen | ||
| osmoappdesc.py | ||
README
This is an implementation of Packet Control Unit (PCU) according to TS 04.60 The PCU is part of BSS, so it connects directly to SGSN. == Current limitations == * No PFC support * No fixed allocation support * No extended dynamic allocation support * No unacknowledged mode operation * No PCCCH/PBCCH support * Only single slot assignment on uplink direction * No half-duplex class support (only semi-duplex) * No handover support * No measurement support * No TA loop * No power loop * No CS loop * No EGPRS