ITTC Project

AAL2 Call/Connection Control Signaling

Project Award Date: 05-01-1998


ITTC researchers are developing a new AAL (ATM Adaptation Layer for composite users) that will allow the multiplexing of several small data units. AAL2 will allow messages that are sent and received from different sources/connections into a single ATM VC connection. This will limit packetization delay for compressed voice without wasting transmission bandwidth due to partial filling of ATM cells. The original motivation for AAL2 was to support compressed voice found in many cellular systems, but voice trunking and ATM to the desktop have been added as potential AAL2 applications.

Although AAL2 is primarily designed for Deterministic Bit Rate (DBR) type traffic, it also allows non-DBR traffic to be multiplexed and transported over a single ATM VC. Although standardization aspects have not been addressed for data applications using AAL2, there are legitimate reasons to explore the feasibility of applying AAL2 in medium-packet-size data applications.

AAL2 could maximize the possible segmentation efficiency. For data applications whose packet size varies from very small to medium size, AAL2 may be a more efficient segmentation scheme than AAL5, since the AAL2 overhead is smaller than the AAL5 trailer overhead. Thus AAL2 may be more bandwidth efficient than AAL5 for many applications.

This new technology could provide economic advantages along with management simplicity. If multiplexing for multiple user applications can be achieved within one ATM VC, a user can buy a single VC instead of one VC for each individual application. This situation may fit in the home broadband environment where multiple user applications are supported and may be true for enterprise networks. Also, wireless devices may be able to eliminate implementing both AAL2 and AAL5 on selected ATM interfaces by acceptable compromise.

KUs Rapidly Deployable Radio Network (RDRN) system can be used for the study of AAL2 for VBR and UBR. The RDRN system is a flexible wireless ATM system that incorporates a software ATM switch and flexible control implementation. This flexibility makes it ideal for AAL2 protocol research.


Faculty Investigator(s): Joseph Evans (PI)

Project Sponsors

Primary Sponsor(s): Sprint

Partner with ITTC

The Information and Telecommunication Technology Center at the University of Kansas has developed several assistance policies that enhance interactions between the Center and local, Kansas, or national companies. 

ITTC assistance includes initial free consulting (normally one to five hours). If additional support is needed, ITTC will offer one of the following approaches: 

Sponsored Research Agreement

Individuals and organizations can enter into agreements with KUCR/ITTC and provide funds for sponsored research to be performed at ITTC with the assistance of faculty, staff and students.

Licensing and Royalty/Equity Agreement

An ITTC goal is the development of investment-grade technologies for transfer to, and marketing by, local, Kansas, and national businesses. To enhance this process, the Center has developed flexible policies that allow for licensing, royalty, and equity arrangements to meet both the needs of ITTC and the company.

Commercialization Development

Companies with a technology need that can be satisfied with ITTC's resources can look to us for assistance. We can develop a relationship with interested partners that will provide for the development of a technology suited for commercialization.

ITTC Resource Access

ITTC resources, including computers and software systems, may be made available to Kansas companies in accordance with the Center's mission and applicable Regents and University policies.

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