Wireless over CATV: an alternative wireless topology

Aerial propagation of radio waves is the most important constraint in the design planning and implementation of wireless systems and services. The major characteristics of an aerial radio path are its length and it´s LOS (line of sight) vs. NLOS (non-LOS) situation, where short length and LOS are the superior states. On the contrary the economy of public communication services dictates long NLOS topologies. The common design approach to bridge the gap and to enable proper radio reception in the poor propagation conditions is to incorporate heavy signal processing and radio technologies. A wide family of such techniques is available, the most known are: equalization, RAKE reception, diversity methods (time, frequency, space, polarization), complex multiple spread spectrum and multi-carrier access methods, spatial processing, and this is only a partial list. The new alternative presented here addresses the propagation problem by the introduction of the hybrid coax air (HCA) radio channel. The radio propagation characteristics of the new channel are excellent since its aerial portion is very short and LOS. Furthermore, the transition to the NLOS long radio path is implemented through the perfect propagation properties of the coaxial cables. The global wide spread of the existing cable networks, their density, their supreme capacity as radio carriers and their enormous unused capacity motivate the utilization of the new alternative together with the benefits to the wireless potential services. The realization of the HCA radio channel in existing CATV networks is pending to some modification at the network. The potential benefits to the wireless services are the theme of this paper. It is presented here in relation to the two leading wireless applications: cellular and Wi-Fi. Both of them, together or separately, can use the HCA channels in order to generate new services and applications. The motivation for and the technical properties of wireless over cable networks are discussed in the paper.