CDMA2000, also known as IMT-CDMA Multi-Carrier or IS-2000 is a technology for CDMA operators to advance their cdmaOne/IS-95 to 2.5G and 3G cellular networks. 3GPP2, the standard body behind CDMA2000, defines all the network functionalities, interfaces and operation protocols.
As adopted by a lot of operators, CDMA2000 is normally deployed in several phases. The first phase, CDMA2000 1x, supports an average of 144 kbps packet data in a mobile environment. The second release of 1x, called 1x-EV-DO supports data rates up to 2 Mbits/sec on a dedicated data carrier. Finally, 1x-EV-DV will support even higher peak rates, simultaneous voice and high-speed data, as well as improved Quality of Service mechanisms.
Major CDMA2000 network elements and interfaces are shown in the following figure.
A summary of all CDMA2000 protocols are listed as follows:
- A1: A1 Signaling, SCCP, MTP3, MTP2, MTP1
- A3: A3 Signaling, TCP, IP, AAL5, SSSAR, AAL2
- A7: A7 Signaling, TCP, IP, AAL5
- A8: GRE, IP, PPP
- A9: A9 signaling TCP, UDP, IP
- A10: GRE, IP, PPP
- A11: A11 signaling, UDP, IP, PPP, Mobile IP
- A12: RADIUS, UDP, IP, PPP
- A13: A13 Signaling, TCP/UDP, IP
- A14: A14 Signaling, TCP/UDP, IP
- A15: A15 Signaling, TCP/UDP, IP
- 3GPP2 IOS 3.x and IOS 4.x
- Other Protocols: PPP in HDLC-likeFraming, IPCP, Diameter, IKE
2. A1 Interface
The A1 interface carries signaling information between the Call Control (CC) and Mobility Management (MM) functions of the MSC and the call control component of the BS (BSC). The application signaling protocol used over this interface is the Base Station Application Part (BSAP). BSAP includes two sub-application parts; the BS management application part (BSMAP), and the direct transfer application part (DTAP).
The BS Management Application Part (BSMAP) supports all Radio Resource Management and Facility Management procedures between the MSC and the BS, or to a cell(s) within the BS. BSMAP messages are not passed to the MS, but are used only to perform functions at the MSC or the BS. A BSMAP message (Complete Layer 3 Information) is also used together with a DTAP message to establish a connection for a MS between the BS and the MSC, in response to the first layer 3 air interface message sent by the MS to the BS for each MS system request.
The Direct Transfer Application Part (DTAP) messages are used to transfer call processing and mobility management messages between the MSC and BS. DTAP messages carry information that is primarily used by the MS. The BS maps the DTAP messages going to and coming from the MSC from/into the appropriate air interface signaling protocol.
BSMAP Messages
- Additional Service Notification
- ADDS Page
- ADDS Page Ack
- ADDS Transfer
- ADDS Transfer Ack
- Assignment Complete
- Assignment Failure
- Assignment Request
- Authentication Request
- Authentication Response
- Base Station Challenge
- Base Station Challenge Response
- Block
- Block Acknowledge
- BS Service Request
- BS Service Response
- Clear Command
- Clear Complete
- Clear Request
- Complete Layer 3 Information
- Feature Notification
- Feature Notification Ack
- Handoff Command
- Handoff Commenced
- Handoff Complete
- Handoff Failure
- Handoff Performed
- Handoff Request
- Handoff Request Acknowledge
- Handoff Required
- Handoff Required Reject
- PACA Command
- PACA Command Ack
- PACA Update
- PACA Update Ack
- Paging Request
- Privacy Mode Command
- Privacy Mode Complete
- Radio Measurements for Position Request
- Radio Measurements for Position Response
- Rejection
- Rejection
- Reset Acknowledge
- Reset Circuit
- Reset Circuit Acknowledge
- SSD Update Request
- SSD Update Response
- Status Request
- Status Response
- Transcoder Control Acknowledge
- Transcoder Control Request
- Unblock
- Unblock Acknowledge
- User Zone Reject
DTAP Messages
- Additional Service Request
- ADDS Deliver
- ADDS Deliver Ack
- Alert With Information
- Authentication Request
- Authentication Response
- Base Station Challenge
- Base Station Challenge Response
- CM Service Request
- Connect
- Flash with Information
- Flash with Information Ack
- Location Updating Accept
- Location Updating Reject
- Location Updating Request
- Paging Response
- Parameter Update Confirm
- Parameter Update Request
- Rejection
- Service Release
- Service Release Complete
- SSD Update Request
- SSD Update Response
- Status Request
- Status Response
- User Zone Reject
- User Zone Update
- User Zone Update Request
3. A2 Interface
The A2 interface carries 64/56 kbps PCM information (voice/data) or 64 kbps Unrestricted Digital Information (UDI, for ISDN) between the Switch component of the MSC and one of the following:
- the channel element component of the BS (in the case of an analog air interface), or
- the Selection/Distribution Unit (SDU) function (in the case of a voice call over a digital air interface),
4. A3 Interface
The A3 interface carries coded user information (voice/data) and signaling information between the SDU function and the channel element component of the BS (BTS). This interface is composed of signaling and user traffic sub-channels between two BSCs. It provides the ability to establish and remove A3 traffic connections.
A3 signaling messages are listed as follows:
- A3-Connect
- A3-Connect Ack
- A3-Remove
- A3-Remove Ack
- A3-Drop
- A3-Propagation Delay Measurement Report
- A3-IS-95 FCH Forward
- A3-IS-95 FCH Reverse
- A3-Physical Transition Directive
- A3-Physical Transition Directive Ack
- A3-IS-2000 FCH Forward
- A3-IS-2000 FCH Reverse
- A3-Traffic Channel Status
- A3-IS-2000 DCCH Forward
- A3-IS-2000 DCCH Reverse
- A3-IS 2000 SCH Forward
- A3-IS 2000 SCH Reverese
- A3-FCH Forward Traffic Frame
- A3-DCCH Forward Traffic Frame
- A3-FCH Reverse Traffic Frame
- A3-DCCH Reverse Traffic Frame
- A3-SCH Reverse Traffic Frame
5. A5 Interface
The A5 interface carries a full duplex stream of bytes between the MSC and the SDU function.
6. A7 Interface
The A7 interface provides direct BS to BS signaling for the support of an efficient soft handoff procedure.
A7 signaling messages are:
- A7-Handoff Request
- A7-Handoff Request Ack
- A7-Drop Target
- A7-Drop Target Ack
- A7-Target Removal Request
- A7-Target Removal Response
- A7-Source Transfer Performed
- A7-Reset
- A7-Reset Acknowledge
- A7-Paging Channel Message Transfer
- A7-Paging Channel Message Transfer Ack
- A7-Access Channel Message Transfer
- A7-Access Channel Message Transfer Ack
- A7-Burst Request
- A7-Burst Response
- A7-Burst Commit
- A7-Burst Release
7. A8 Interface
The A8 interface carries user traffic between the BS and the PCF. The A8 interface uses the Generic Routing Encapsulation (GRE) protocol to provide a mechanism for encapsulating arbitrary packets within an arbitrary transport protocol for traffic delivery between BSC and PCF.
8. A9 Interface
The A9 interface carries signaling information between the BS and the PCF. The A8/A9 interfaces support mobility between BSCs under the same PCF.
The A9 interface signaling messages are listed below:
- A9-Setup A8
- A9-Connect A8
- A9-Disconnect A8
- A9-Release A8
- A9-Release A8 Complete
- A9-BS Service Request
- A9-BS Service Response
- A9-AL Connected
- A9-AL Connected Ack
- A9-AL Disconnected
- A9-AL Disconnected Ack
- A9-Short Data Delivery
- A9-Short Data Ack
- A9-Update-A8
- A9-Update-A8-Ack
- A9-Version Info
- A9-Version Info Ack
9. A10 Interface
The A10 interface carries user traffic between the PCF and the PDSN. The A10 interface uses the Generic Routing Encapsulation (GRE) protocol to provide a mechanism for encapsulating arbitrary packets within an arbitrary transport protocol for traffic delivery between PCF and PDSN.
10. A11 Interface
The A11 interface carries signaling information between the PCF and the PDSN for packet data services and provides a signaling connection between a PCF and PDSN pair (A11). A11 signaling messages are also used for passing accounting related and other information from the PCF to the PDSN. The A10/A11 interfaces support mobility between PCFs under the same PDSN.
The A11 signaling messages are
- Registration Request
- Registration Reply
- Registration Update
- Registration Acknowledgment
11. A12 Interface
The A12 interface uses RADIUS protocol for authentication purposes.
12. A13 Interface
The A13 protocol is responsible for information exchange between the source and target AN. The protocol is divided up into information from the target to source direction, and information from the source to the target direction. Signaling over the A13 interface requires a reliable transport protocol and appropriate addressing and routing mechanisms to deliver messages from the target to source destination.
All A13 messages are listed below
- A13-Session Information Request
- A13-Session Information Confirm
- A13-Session Information Reject
- A13-Session Information Response
13. A14 Interface
The A14 interface between the AN and the SC/MM function of the PCF is used for performing HRPD Session and HRPD mobility related operations. Procedures included in A14 interface functions are
• UATI assignment procedure.
• General updating procedure.
• Terminal authentication.
• Session release.
• Session information updating procedure.
• Paging procedure.
For supporting above procedures, the A14 interfaces uses the following messages:
- General Update
- General Update Complete
- Authentication Command
- Authentication Request
- Authentication Response
- Authentication Completed
- Authentication Completed Ack
- UATI Request
- UATI Assignment
- UATI Complete
- UATI Complete Ack
- UATI Assignment Failure
- Session Release
- Session Release Complete
- Paging Request
- Paging Request Ack
- Paging Response
- Paging Response Ack
- Session Information Update
- Session Information Update Ack
- Session Release Command
- Authentication Failure
- Authentication Failure Ack
- Keep Alive Request
- Keep Alive Request Ack
14. A15 Interface
The A15 interface is used for sending paging request messages from the AN that manages the registered sector to the ANs that send paging messages over the air. This interface is used for inter AN paging.
All messages used in A15 signaling are as follows:
- Paging Request
- Paging Response
- Paging Response Ack
