LTE, LTE-Advanced and WiMAX: Towards IMT-Advanced Networks

Network Entry in IEEE 802.16m

Under IEEE 802.16m, an AMS transitions between four states that are shown in Figure 5.3. These states are:

• Initialization State;
• Access State;
• Connected State; and
• Idle State.

The network entry and initial ranging procedures are performed while an AMS is in Initialization and Access States. Periodic and other (e.g., for handover) ranging procedures are performed while an AMS is in a connected state.

The procedures can be related to the states as follows. When an AMS is in the initialization state it performs the following tasks:

• a) Scanning and synchronization;
• b) Super-Frame Header Acquisition;
• c) Cell selection decision;

Once b) and c) are performed, the AMS transitions to the Access State and performs the following tasks.

• d) Ranging and uplink synchronization;
• e) Pre-authentication capability negotiation (if applicable);
• f) MS authentication, authorization and key exchange;
• g) Capability exchange and registration with serving ABS;
• h) Initial service flow establishment.

An AMS transitions to the Connected State once h) is performed.

For multicarrier operation, an AMS only attempts network entry and initial ranging with a fully configured carrier. Detecting an A-PREAMBLE, the AMS would decode the SFH and other system parameters and configuration information by which the ABS indicates its support for the multicarrier feature. Once a candidate primary carrier is selected by the AMS, network entry proceeds normally. If successful, the same carrier ...