Hi All,
We have noticed that the PCU sends invalid block number to L1 in DSP leading to unexpected message warning in DSP "GsmL1_PhDataReq(1) : Unexpected burst (Invalid blockNumber) [2!=1, SAPI 21-21]]".
After an investigation, we observe that the 'pcu_rx_rts_req' function in pcu_l1_if.cpp receives invalid block number from BTS.
Looking at the BTS side, the calculation of L1SAP_FN2PTCCHBLOCK defined as '#define L1SAP_FN2PTCCHBLOCK(fn) ((fn / 52) & 7)' does not seem to be valid for expected PTCCH block numbers B0, B1,B2,B3 defined in Table 6 in TS 05.02 version 8.11.0.
What do you think about re-define the calculation of the L1SAP_FN2PTCCHBLOCK?
Regards,
Minh-Quang Nguyen
Concepteur logiciel | Software designer GSM/Network
T. 418 914-7484 x2296 | 1 855 914-7484 | F. 418 914-9477 2150, Cyrille-Duquet, Québec (Québec) G1N 2G3 CANADA
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Hi Minh,
first of all, thanks for helping out in terms of OsmoPCU/OsmoBTS bug hunting, it is much appreciated. It is a collaborative project, after all :)
On Mon, May 02, 2016 at 09:32:12AM -0400, Minh-Quang Nguyen wrote:
After an investigation, we observe that the 'pcu_rx_rts_req' function in pcu_l1_if.cpp receives invalid block number from BTS.
Looking at the BTS side, the calculation of L1SAP_FN2PTCCHBLOCK defined as '#define L1SAP_FN2PTCCHBLOCK(fn) ((fn / 52) & 7)' does not seem to be valid for expected PTCCH block numbers B0, B1,B2,B3 defined in Table 6 in TS 05.02 version 8.11.0.
What do you think about re-define the calculation of the L1SAP_FN2PTCCHBLOCK?
If you find the existing calculation is not agreeing with the specification (I'd have to re-read the spec, but I trust you when you say that), I would appreciate if you could send a patch (or patch series) that changes it to be within the spec. If the calculation is more complex, better use a separate function than the simplistic macro.
Thanks in advance!
Regards, Harald
On 02 May 2016, at 15:32, Minh-Quang Nguyen minh-quang.nguyen@nutaq.com wrote:
Hi All,
We have noticed that the PCU sends invalid block number to L1 in DSP leading to unexpected message warning in DSP “GsmL1_PhDataReq(1) : Unexpected burst (Invalid blockNumber) [2!=1, SAPI 21-21]]”.
After an investigation, we observe that the ‘pcu_rx_rts_req’ function in pcu_l1_if.cpp receives invalid block number from BTS. Looking at the BTS side, the calculation of L1SAP_FN2PTCCHBLOCK defined as ‘#define L1SAP_FN2PTCCHBLOCK(fn) ((fn / 52) & 7)’ does not seem to be valid for expected PTCCH block numbers B0, B1,B2,B3 defined in Table 6 in TS 05.02 version 8.11.0.
How do you execute the PCU? By opening the PDCH queue directly or by getting all information from the BTS?
holger
Hi Holger,
The PDCH queue is directly connected to the PCU ( the PCU was compiled with direct L1 communication)
Minh-Quang Nguyen
Concepteur logiciel | Software designer GSM/Network
T. 418 914-7484 x2296 | 1 855 914-7484 | F. 418 914-9477 2150, Cyrille-Duquet, Québec (Québec) G1N 2G3 CANADA
minh-quang.nguyen@nutaq.com www.nutaq.com
QUEBEC MONTREAL NEW YORK
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-----Original Message----- From: Holger Freyther [mailto:holger@freyther.de] Sent: Monday, May 02, 2016 3:41 PM To: Minh-Quang Nguyen Cc: osmocom-net-gprs@lists.osmocom.org; Yves Godin Subject: Re: PCU sends invalid block number to L1
On 02 May 2016, at 15:32, Minh-Quang Nguyen minh-quang.nguyen@nutaq.com wrote:
Hi All,
We have noticed that the PCU sends invalid block number to L1 in DSP leading to unexpected message warning in DSP “GsmL1_PhDataReq(1) : Unexpected burst (Invalid blockNumber) [2!=1, SAPI 21-21]]”.
After an investigation, we observe that the ‘pcu_rx_rts_req’ function in pcu_l1_if.cpp receives invalid block number from BTS. Looking at the BTS side, the calculation of L1SAP_FN2PTCCHBLOCK defined as ‘#define L1SAP_FN2PTCCHBLOCK(fn) ((fn / 52) & 7)’ does not seem to be valid for expected PTCCH block numbers B0, B1,B2,B3 defined in Table 6 in TS 05.02 version 8.11.0.
How do you execute the PCU? By opening the PDCH queue directly or by getting all information from the BTS?
holger
osmocom-net-gprs@lists.osmocom.org
-
Harald Welte -
Holger Freyther -
Minh-Quang Nguyen