The ATM Forum has updated two of its physical layer specifications. The revised DS3 Physical Layer specification, which was approved in February, now sets out how Asynchronous Transfer Mode cells should be loaded into a DS3 transmission system payload. The Forum believes that a 9% gain in pay-load capacity (representing a 9% cost saving) can be achieved over the previous method used by the Forum, and by American National Standards Institution. The Forum has also added an addendum to its September 1994 Physical Medium Dependent Interface Specification for 155Mbps Asynchronous Mode over Twisted Pair Cable. This details the cable types to which the specification can be applied.
