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PHS 1.9 Ghz: Personal Hand phone System is popularly used in Japan only because of its low power usage and does not re-
quire a SIM card. The system is primarily intended for its voice calls with data support until 256 Kbps. Nevertheless, PHS is
gradually being phrase out by 3 G networks.
2.2.6 Broadband Wireless Access BWA
BWA can support a wide range of services because of its ultra- high speed. Generally BWA is adopted for medium to long
range distribution and the carrier frequency can vary between couples of Ghz to 40 Ghz based on local bylaws. The develop-
ment of BWA is legislated by the IEEE 802.16 Working Group on Broadband Wireless Access Standards. However, IEEE
802.16 does determine the prerequisites of frequency bands or certification of equipment. Fixed or portable WiMAX operating
at 2.4 to 5 Ghz ISM band is compatible with both IEEE 802.16e and ETSI HiperMAN wireless. A metropolitan Area Network
MAN principle which covers several kilometers is gaining popularity as of late because of its high level of interoperability.
Local Multipoint Distribution Service LMDS which is a common BWA operation is used for
fixed networking which implies that mobility support is very constrained. The major dis-
tinction between MNDS and Fixed WiMAX is the operating frequency which paves the way to a signi
ficant enhancement in channel bandwidth. LMDS is able to support over 512 Mbps for
transmitting large amounts of data. Since the radios possess a 90
˚ field of view, it is practical to utilize four radios for omnidi- rectional 360
˚ coverage. The features of LMDS make it espe- cially suitable for telemedicine backbone support. The
expression backbone denotes the medium which accommo- dates a major trunk line for interconnecting an array of local
area networks LANs and also equipment over a vast area. For instance, an organization such as a hospital may have numerous
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buildings which represent different units that are interlinked to a network backbone as indicated in Figure 2.6.
Figure 2.6 Network connecting the hospital 2.2.7 Satellite Networks
These are more advanced and costly networking as launching a satellite accurately above the earth is an expensive affair. How-
ever, its operating guideline is uncomplicated. A communica- tion satellite or comsat is placed into a pre-determined orbit
above the earth. The orbit of the satellite will depend on the pre- ferred coverage area. The comsat functions as a point-to-point
microwave radio relay which facilitates a radio connection be- tween two distinct Earth stations. Satellites are often utilized in
WAN wide area networks. Although a satellite cannot with- stand natural interference for example solar storms, it is indeed
very reliable and gives appreciable speed interfaces. Despite the fact that such features may seem apt for remote robotic surgery
considering the endless amount of data which need to be trans-
