TIA TIA-856.400-C

Introduction

General Overview

The Connection Layer controls the state of the air-link, and itprioritizes the traffic that is sent over it.

This section presents the default protocols for the ConnectionLayer. With the exception of the Overhead Messages Protocol, eachof these protocols can be independently negotiated at the beginningof the session.

The access terminal and the access network maintain a connectionwhose state dictates the form in which communications between theseentities can take place. The connection can be either closed oropen:

• Closed Connection: When a connection is closed, the accessterminal is not assigned any dedicated air-link resources.Communications between the access terminal and the access networkare conducted over the Access Channel and the Control Channel.

• Open Connection: When a connection is open, the accessterminal can be assigned the Forward Traffic Channel, and isassigned a Reverse Power Control Channel and a Reverse TrafficChannel. Communications between the access terminal and the accessnetwork are conducted over these assigned channels, as well as overthe Control Channel.

The Connection Layer provides the following connection-relatedfunctions:

• Manages initial acquisition of the network.

• Manages opening and closing of connections.

• Manages communications when connection is closed and when aconnection is open.

• Maintains approximate access terminal’s location in eitherconnection states.

• Manages radio link between the access terminal and the accessnetwork when connection is open.

• Performs supervision both when the connection is open and whenit is closed.

• Prioritizes and encapsulates transmitted data received fromthe Session Layer and forwards it to the Security Layer.

• De-capsulates data received from the Security Layer andforwards it to the Session Layer.

The Connection Layer performs these functions through thefollowing protocols:

• Air Link Management Protocol: This protocol maintains theoverall connection state in the access terminal and the accessnetwork. The protocol can be in one of three states, correspondingto whether the access terminal has yet to acquire the network(Initialization State), has acquired the network but the connectionis closed (Idle State), or has an open connection with the accessnetwork (Connected State). This protocol activates one of thefollowing three protocols as a function of its current state.

• Initialization State Protocol: This protocol performs theactions associated with acquiring an access network.

• Idle State Protocol: This protocol performs the actionsassociated with an access terminal that has acquired the network,but does not have an open connection. Mainly, these are keepingtrack of the access terminal’s approximate location in support ofefficient Paging (using the Route Update Protocol), the proceduresleading to the opening of a connection, and support of accessterminal power conservation.

• Connected State Protocol: This protocol performs the actionsassociated with an access terminal that has an open connection.Mainly, these are managing the radio link between the accessterminal and the access network (handoffs, handled via the RouteUpdate Protocol), and the procedures leading to the close of theconnection.

In addition to the above protocols, which deal with the state ofthe connection, the Connection Layer also contains the followingprotocols:

• Route Update Protocol:This protocol performs the actionsassociated with keeping track of an access terminal’s location andmaintaining the radio link between the access terminal and theaccess network. This protocol performs supervision on thepilots.

• Overhead Messages Protocol: This protocol broadcasts essentialparameters over the Control Channel. These parameters are shared byprotocols in the Connection Layer as well as protocols in otherlayers. This protocol also performs supervision on the messagesnecessary to keep the Connection Layer functioning.

• Packet Consolidation Protocol: This protocol consolidates andprioritizes packets for transmission as a function of theirassigned priority and the target transmission channel.

The Air Link Management Protocol, its descendants and theOverhead Messages Protocol are control protocols. The PacketConsolidation Protocol operates on transmitted and receiveddata.

Edition:

C

Published:

02/01/2011

Number of Pages:

412

File Size:

1 file , 5.5 MB