ATM for disadvantaged tactical links

Asynchronous transfer mode (ATM is an emerging transmission/switching technology which may provide the means for opening up the growing communication traffic jam to/from the warrior. The ATM efficiently utilizes channel bandwidth by asynchronously multiplexing small packets (53-byte cells) of information and switching them rapidly through a shared network. The benefits of using an ATM network for tactical communications applications are largely due to its inherent flexibility in carrying voice, video, data, and imagery without regard to specific format. A major handicap in the application of ATM to the tactical environment is the high channel bit error rate. Although some payload errors can be tolerated, for ATM to survive in the battlefield it is essential that the cell header, which contains the routing information, be protected from errors. One approach being considered for the tactical ATM error control problem is to provide a strong error correcting code in the header, and let higher level user-provided protocols control payload errors on a case by case basis. Since the header occupies only about 10% of the cell, the added redundancy required to protect the header would not have a major impact on the limited bandwidth available. GTE is currently planning experiments to obtain realistic performance estimates. Specifically, experiments are being designed using a low-speed cell-bearing interface card with a SPANet switch operating over tactical radio and cable links to determine how candidate error control techniques will affect the performance of tactical ATM communication networks