HIPERLAN System Performance Under DCA and FCA

HIPERLAN is a high speed wireless LAN standard recently adopted by ETSI. It operates in 150 MHz of spectrum in the 5 GHz band, with up to five TDD channels provided for duplex data transmission at up to 23.5 Mb/s. This paper shows that in the presence of cochannel cells and full link utilisation, HIPERLAN performs poorly when using its DCA–type Clear Channel Assessment (CCA) scheme, and that the target performance levels are only achievable under optimal FCA–type channel assignments. Two main factors contribute to this poor performance: HIPERLAN has insufficient channels to meet C/I constraints in the presence of cochannel cells; and the CCA scheme results in poor channel distributions.