CDMA technology has undergone many stages of revolution to offer improved voice and data service to the end users.
In order to deliver both voice as well as data service with very high transmission rate, CDMA network has incorporated many new nodes and protocols with respect to old 2G or 2.5G networks (GSM and GPRS network).
The latest 3G technology, called CDMA 2000 1xEV-DV is capable of delivering integrated voice and simultaneous multimedia services at peak data rates of 3.09 Mbps to the end subscriber.
IS-2000 is the signaling standard, which defines protocols for several critical 3G CDMA interfaces pertaining to packet transmission namely A1, A7, A9 and A11 (shown below). An IS-2000 compliant Mobile Station (MS) can select either packet-switched data (PSD) or circuit-switched data (CSD) transport. CSD has maximum rate of 19.2 kbps and is delivered over traditional TDM circuits. PSD offers higher data rate for multimedia services. For each data session, a PPP (Point-to-Point Protocol) session is created between the Mobile Station and the Packet Data Serving Node (PDSN).
The CDMA2000 network comprises of the Radio Access Network (RAN) and the Core Network. A Mobile Station accesses the CDMA2000 network through the RAN. The RAN consists of the Air Link, Base Station Transceiver Subsystem (BTS), Base Station Controller (BSC), and a part of Packet Control Function (PCF). The RAN maps the Mobile Station ID to a unique link layer identifier that is used to communicate with the PDSN, validate the MS for access service, and maintain the established transmission links. The BTS connects to the BSC through un-channelized T1s and A-bis protocols (proprietary to a particular vendor) based on HDLC.
The BSC routes PSD and CSD messages between the cell sites and the MSC. In addition, the BSC is also responsible for mobility management. It connects to each Mobile Telephone Exchange (MTX) using channelized T1 lines for voice and circuit switched data; and to un-channelized T1 lines for signaling and control messages to the PDSN using Ethernet protocols.
The PCF routes IP data packets between the MS and the PDSN. The PDSN is the Gateway from the RAN into the public and private networks. The PDSN can act as either a standalone Network Access Server (NAS), Home Agent (HA) or a Foreign Agent (FA).
GL's CDMA Protocol Analyzer can be used to analyze and view protocols across A1 (between Base Station Controller and Mobile Switching Centre), A3 and A7 (between two Base Station Controllers), A9 (between Base Station Controller and Packet Control Function), and A11 (between Packet Control Function and PDSN) signaling interfaces as depicted in the above figure
- Between BSC and BTS: Abis
- Between BSC and BSC: A3 and A7 (also known as 'Ater')
- Between BSC and PCF: A9 (also known as 'Aquinter')
- Between BSC and MSC: A1 (also known as 'A')
- Between PCF and PDSN: A11 (also known as 'Aquater')
GL Communications supports the following types of CDMA analyzers:
- Real-time CDMA Analyzer (Pre-requisites: GL's field proven E1 or T1 internal cards or USB Laptop E1 or T1 external units, required licenses and Windows XP (or higher) Operating System)
- Offline CDMA Analyzers (Pre-requisites: Hardware dongle and Windows XP (or higher) Operating System)
Additional feature supported by Real-time CDMA Analyzer
- Supports decoding of Ethernet-based protocols (across Aquinter and Aquater interfaces), ATM based protocols (across Ater interface), & HDLC based protocols (across A interface).
- Allows customized filtering/searching of the captured data (real-time/offline) by setting various parameters such as VPI/VCI, Payload Type, MAC layer address, Frame length, IP address, Port number and so on based on the interfaces chosen.
- Displays Summary, Detail, Hex-dump, Statistics, and Call Trace Views, the contents of this view can also be copied to clipboard.
- Summary View displays Device Number, Time Slots:, SubChannels, Frame Number, Time, Frame Length etc in a tabular format.
- Detailed View displays decodes of user selected frame from the Summary View.
- Hex dump view displays raw frame data as hexadecimal and ASCII octet dump, the contents of this view can also be copied to clipboard.
- Statistics View displays statistics based on frame count, byte count, frames/sec, bytes/sec and so on for the entire data capture.
- Call Detail Record View displays called/ calling number, released calls, call status, & more.
- Capability to export Summary View details to comma separated values (CSV) format subsequent import into a database or spreadsheet.
- Capability to export detail decode information to an ASCII.
- Ability to edit.ini file to configure the A3 A7 IOS related parameters in order to get proper decoding of protocols across A3A7 interface.
- Supports simultaneous decode of multiple streams of CDMA traffic on different T1/E1 channels.
- Any protocol field can be added to the summary view, filtering, and search features providing users more flexibility to monitor required protocol fields.
- Remote monitoring capability using GL's Network Surveillance System.
Additional features supported by Offline CDMA Analyzer:
- Supports capturing and decoding of Ethernet-based protocols (across Aquinter and Aquater or A9 A11 interfaces), ATM based protocols (across Ater or A3 A7 interfaces), & HDLC based protocols (across A or A1 interface).
- Multiple streams of CDMA traffic on various T1/E1 channels can be simultaneously decoded with different GUI instances.
- For A3 A7 interfaces,
- Captures, decodes, filters, and reassembles (with or without Inverse Multiplexing option) AAL-2 and AAL-5 frames in real-time, from within the ATM cells according to user defined VPI/VCI.
- ATM raw data capturing requires user to specify timeslots, bit inversion, octet bit reversion, user/network side, ATM mapping, scrambling, and inverse multiplexing options.
- Streams may be captured on the selected time slots (contiguous or non-contiguous) and on full bandwidth.
- Unscrambling of ATM cells based on SDH Xˆ43 + 1 algorithm.
- For A1,
- Frames captured can be filtered real-time based on length of frames (FISSU – Length as 5 and LSSU – Length as 7) can be set.
- Supports decoding of frames with FCS of 16 bits and 32 bits, or none.
- Data transmission rate starting from 8kbps to N*64kbps is supported.
- Timeslots selection can be contiguous or non-contiguous.
- Call Detail Recording feature includes data link groups that help in defining the direction of the calls in a given network. and form logical groups comprised of unidirectional (either 'Forward' or 'Backward') data links.
- For A9 and A11,
- Frames captured can be filtered real-time based on Source IP address, Destination IP address, Mac Layer Address, Source/Destination port no etc can be applied.
- Trace files for analysis can be loaded through simple command-line arguments.
- Multiple trace files can be loaded simultaneously with different GUI instances for offline analysis.