openbts_4.0.0.tar.gz_5G_OpenBTS 4.0_openbts_usrp_usrp c++

Kyles Blackberry is Blackberry 9700 Speed tests: From mobileSpeedTest.com: Original: Your speed: 5.166 Kbps Your latency: 3.057 seconds Transferred 100KB in 154.86 seconds. With ganged TBFs, TBF wrap-around disabled, GPRS.Counters.N3105=3, GPRS.TBF.Retry=4, GPRS.SinglePduMode=0. The thing is still getting alot of 3105 errors. And in general it gets cause=1 too, although not during this test, but before. Your speed: 6.984 Kbps Your latency: 2.09 seconds Transferred 100KB in 114.55 seconds. Another try: Your speed: 7.539 Kbps Your latency: 2.583 seconds Transferred 100KB in 106.11 seconds. Then I tried allowing TBF wrap-around and it went down! Your speed: 6.383 Kbps Your latency: 2.34 seconds Transferred 100KB in 125.34 seconds. Got 11 retries during the test, Note: GSM04.08 (L3 Procedures) and GSM04.18 (L3 messages) replaced by 44.18 + 24.08 4.08 has a state machine picture in 4.1.2, and GMM states a little after. 24.007 7.1.1 has lots of state machines including same state machine picture, but I dont think they are useful. 3.64 6.2 has the DTM state machine picture. 23.060 6.1 has a description of GMM states (PMM_whatever) for 3G-SGSN. 24.007 11.2.4 - Lists IEI formats so you can tell how to skip an unrecognized IEI. 3.03 2.6 - how to encode TLLI. Measurement Reports: 45.008 10.1.4: in Network Control Order 2 (the one I have been using) if the MS detects a downlink signalling failure or random access failure (as defined in 44.018/44.060) the MS will perform autonomous cell reselection. This may have been what was happening when the MS would stop listening to the BTS for 2 second straight. RA Update - for GPRS. LA Update - for CS calls. Combined RA/LA update permitted at SGSN. DRX mode and paging groups covered in GSM05.02. MS tells DRX mode to SGSN in the GPRS Attach or RA Update messages. Just what does the sgsn think it is going to do with it? GPRS: Jean Samuel - French guy funding Russians to develop GPRS. The BCS Block Check Sequence shown in GSM03.64 6.6.4 figure 20 is just the 40 bit checksum added by transmit(). PDP Context Activiation: Getting IP address: 24.008 6.1.2 GSM 4.64 - LLC layer. Note from man 7 tcp: tcp_frto (integer; default: 0; since Linux 2.4.21/2.6) Enables F-RTO, an enhanced recovery algorithm for TCP retransmission time- outs (RTOs). It is particularly beneficial in wireless environments where packet loss is typically due to random radio interference rather than inter- mediate router congestion. See RFC 4138 for more details. This file can have one of the following values: 0 Disabled. 1 The basic version F-RTO algorithm is enabled. 2 Enable SACK-enhanced F-RTO if flow uses SACK. The basic version can be used also when SACK is in use though in that case scenario(s) exists where F-RTO interacts badly with the packet counting of the SACK-enabled TCP flow. Before Linux 2.6.22, this parameter was a Boolean value, supporting just values 0 and 1 above. RadioResource.cpp: AccessGrantResponder() serviceLoop() TCHFACCHL1Encoder::dispatch() - does TCH data pushing. mDemuxTable in TRXManager.cpp, calls writeLowSideRx in a L1Decoder descendent class. mGPRSFEC Maximum LLC PDU size is 1560 bytes. (GSM04.60 sec9.1.12) Bytes over are discarded in RLC. In unacknowledged mode, LLC-PDUs delivered in the order received, with 0-bits for missing blocks. The minimum payload size (using CS-1) is 20 bytes (see RLCPayloadSize) Therefore, a single PDU may take 78 blocks. There are 1-N downstream L1 physical channels. Each is connected to an L1FEC. An N-PDU is on the network side of SGMS A PDU (aka NS-PDU) is on the downstream side of SGMS, after SNDCP A Segment is a part of a PDU for transmission in an RLC Radio Block. All MAC control functions come from the SGMS via BSSGP. The RLC/MAC is entirely oblivious of PDU content, just passes it to SGMS. The RLC reports downlink packet loss information to SGMS as a Bucket Leak Rate, per BSS (aka BVC on the BSSGP interface), and per MS. Notes: Notes: The SAPMux class defines writeHighSide and writeLowSide An encoder class defines only writeHighSide A decoder class defines only writeLowSide. MAC MODE: Dont understand. For downlink allocation it is: Dynamic allocation, Extended Dynamic allocation, (arent these inapplicable?) Fixed allocation full duplex, Fixed allocation half duplex. TBF Mode: Packet Uplink Assignment, Packet Downlink Assignment, Immediate Assignment TFI goes with TBF. TFI is unique only within a PDCH. For Multislot, TFI is unique in all PDCH of multislot. RLC Mode: Acknowledged or Unacknowledged. (See GSM04.60 11.2.7 Packet Downlink Assignment) Upstream: BSSGSP Definitions: BVCI - BSSGP Virtual Connection ID, 0 = signaling, 1 = PTM (point-to-multipoint) It corresponds to a cell, and can be used instead of routing area id at operators discretion. NSEI+BVCI NSE - Network Service Entity. There is one or more NSE inside the BSS for signaling. NSEI - Network Service Entity Id. I think these correspond to BSS. --- NS-VC - Virtual Connection --- LSP - Link Selector Parameter, something used only inside the BSS or SGSN, and not transmitted, to uniquely identify NS-VC. We wont use it. QoS Profile: specifies transmission mode (acknowledged, etc), bit rate, other stuff. Messages: DL-UNITDATA Includes PDU type (DL-UNITDATA), TLLI, QoS Profile, PDU Lifetime, PDU. optional: IMSI, oldTLLI, PFI (Packet Flow Identifier), etc. Does NOT include LSP, BVCI, NSEI UL-UNITDATA Includes PDU type (UL-UNITDATA), TLLI, BVCI, Cell Identifier, PDU. Does NOT include LSP, BVCI, NSEI. GMM-PAGING-PS/GMM-PAGING-CS (for packet or voice) Includes PDU type (PAGING-PS), QoS Profile, P-TMSI <or> IMSI. Note: If TLLI is specified and already exists within a Radio Context in BSS [because MS has communicated previously] it is used. BVCI <or> Location Area <or> Routing Area <or> BSSArea Indication Optional: P-TMSI, BVCI, Location area, Routing area. GMM-RA-CAPABILITY, GMM-RA-CAPABILITY-UPDATE Astonishingly, the BSS asks the SGSN for this info. GMM-RADIO-STATUS GMM-SUSPEND GMM-RESUME NM-FLUSH NM-LLC-DISCARDED NM-FLOW-CONTROL-BVC NM-FLOW-CONTROL-MS NM-STATUS NM-BVC-BLOCK/NM-BVC-UNBLOCK NM-BVC-RESET NM-TRACE PFM-... Downstream: RACH/AGCH for paging. PDUs via RLC SGSN Uplink: // // OpenBSC endpoint for NS layer packets: libgp/gprs_ns.c:read_nsip_msg // (in OpenBSC, NSIP means NS over IP), which eventually calls: // libgp/gprs_ns.c:gprs_ns_rcvmsg(), in which BSS is identified by three ways: // 1. First it tries using the IP address of the BSS to identify the BSS. // 2. If unrecognized, the NSEI specified in the NS_RESET command is used. // 3. If no NS_RESET ever received, sets NSEI to 0xfffe and proceeds; this works // if there is only one BSS, ever, as in our case. // NS-UNITDATA packets (the only data type) are sent to gprs_ns_rx_unitdata(), // which somehow calls sgsn_ns_cb() (a callback function) // which calls libgp/bprs_bssgp.c:gprs_bssgp_rcvmsg(bci and nsei as params) // which looks up the BTS using the NSEI, then uses: // switch (BVCI) { // case BVCI_SIGNALLING: gprs_bssgp_rx_sign() // case PVCI_PTM: // throw an error // default: gprs_bssgp_rx_ptp(). // gprs_bssgp_rx_ptp() is the main BSSGP function, does this: // switch (pdu_type): // case BSSGP_PDUT_UL_UNITDATA: bssgp_rx_ul_ud(), // which calls bssgp_rx_ul_ud(), which calls gprs_llc_rcvmsg() // case BSSGP_PDUT_FLOW_CONTROL_BVC: bssgp_rx_fc_bvc(); // default: // throw an error // // gprs/gprs_llc.c:gprs_llc_rcvmsg() is the main entry point. // ex