Wireless loops: What are they?

Abstract

Several loop applications of wireless technology are aimed at reducing the cost of deploying communications services ranging from telephone to wideband video. In these applications, wireless links replace a portion of a wireline loop from a central location (a central office or cable headend) to a subscriber. The replacement of labor-intensive wireline technology by complex mass-produced integrated electronics in wireless transceivers is projected to reduce the overall cost of the resulting loop. These wireless loop applications attempt to provide existing communications services or small modifications to existing communications services. A different interpretation of a wireless loop makes use of low-power digital radio technology to provide the last thousand feet or so of a loop. Low-power low-complexity wireless loop technology in small base units can be integrated with network intelligence to provide the fixed-infrastructure network needed to support economical personal communications services (PCS) to small, lightweight, low-power personal voice and/or data communicators. Low-complexity communicators can provide many hours of "talk time" or data transmission time and perhaps several days of standby time from small batteries (< 1.5 oz). Because this application of wireless loop technology can reduce the inherent costs in several parts of a wireline loop, it has the potential to provide convenient widespread PCS at less costs than providing telephone services over conventional wireline loops. This low-power wireless loop application does not fit into any existing communications system paradigm. Wireless technology with tetherless access and wide-ranging mobility, e.g., the personal access communications system (PACS), does not fit the accumulated wisdom of the wireline telephony paradigm. It also does not fit the paradigm of existing cellular radio that has sparsely distributed expensive cell sites, and it is not targeted at fixed video services as is wireless cable. Because a significant change in thinking is required in addressing this new low-power low-complexity widespread wireless loop paradigm, its large economic advantages and service benefits have not yet been embraced by many of the existing communications providers, who appear to be more comfortable pursuing the better-known paradigms of video using wireless cable, or of cellular radio in the guise of high-tier PCS, or in the guise of rapid economical deployment of telephone services in developing nations. This paper discusses the inherent economic advantages and service benefits of low-power low-complexity wireless loop technology integrated with network intelligence aimed at providing economical low-tier PCS to everyone.

Satellite rural communications: telephony and narrowband networks

“…Digital wireless telephone technologies are also defined as WLL, based on their coverage area, technology platform, offered services and technical characteristics, and are called either cellular telephone systems (CTS) or fixed wireless telephony (FWT). Since WLL work at ultra-high frequencies (UHF, 300-3000 MHz) rain is not a problem, and for rural, scattered, semi-fixed users, multipath is not as big a problem as it is in urban applications [2,6]. The area coverage of WLL is usually a few kilometers per cell, depending upon the geography and topography of the terrain.…”

PBX based mobility manager for wireless local loop

“…The di!erence is that the PBX recognizes the dialed DTMF digits as a phone number. The TelephoneTable object is searched to locate the WirelessLine object of 3333333 (see path (1) in Figure 11). If the search indicates that the handset is idle, then the PBX sets both the calling and the called Line objects &busy' and locates the BaseStation object of the BS (i.e.…”

“…Wireless extension to a PBX can be achieved by connecting radio base stations (BSs) to the PM. A BS with large capacity may connect to a DTU (digital trunk unit) card to provide an E1 link or 30 telephone connections (see (1) in Figure 3). A BS with small capacity can connect to LIUs (line interface unit) cards through several subscriber lines (see (2) in Figure 3).…”

“…The PBX marks the WireLine object 10, 6, 32 &busy' and recognizes the dialed DTMF digits as a wireless handset call origination (represented by the special code 1C32) where the calling handset number is 3333333, its password is 7654321, and the called party number is 4444444. The TelephoneTable is searched to locate the WirelessLine object of 3333333 (see path (1) in Figure 13). Suppose that the line object indicates the idle status.…”

“…Recently, many telecommunications operators have been looking for wireless technology to replace parts of the hard-wire infrastructure. The wireless local loop (WLL) technology [1] is considered as the most "tting solution as radio systems can be rapidly developed, easily extended, and are distance insensitive. Since a WLL eliminates the needs (such as wires, poles and ducts) essential for a wired network, it can signi"cantly speed up the installation process.…”