MAC performance for second generation UWB

Next generation UWB design needs higher data rates than those proposed by ECMA-368 in order to be competitive. This paper investigates ECMA-368 MAC performance for extended data rates. It is shown that throughput improves at these extended PHY rates, when PHY frame size (L) is increased to 8190 octets under reasonable BER values. This improvement is a function of the transfer size. L=8190 octets exhibits >16% (>100 Mbps) improvement over L=4095 octets, for large transfers (>65 K octets). This is a worthwhile change since doubling PHY frame size imposes minor incremental complexity relative to the overall effort to support the extended PHY rates. It is shown also that scaling L does not improve throughput for bad channels (PER>12% normalized to 4095 octet payload). To maintain higher throughput under bad channel conditions, we need the ability to increase L without increasing PER. This can be achieved by packing multiple MPDUs into a single PSDU, each with its own frame check sum. This reduces PER by making it a function of the MPDU size and not PHY frame size. Complex MAC changes are needed for such a scheme. Fortunately, this scheme is only needed under bad channel conditions which are not suitable for extended data rates to start with.