written 6.2 years ago by |
A single broadband connection can provide all the necessary telecommunication services like telephone, radio, fax and internet. For deploying a broadband connection fixed wireless access systems are well suited.
Modern fixed wireless systems are generally designed at microwave or millimeter frequencies in the 28 GHz band and higher. At these frequencies, the wavelengths are very small.
In Fixed Wireless Access Systems (FWA), the Wireless Local Loops (WLL) are popular. WLL is also called as fixed wireless loop.
The function of the WLL systems is to make primary access to the telephone networks. It supports subscribers of fixed and known locations.
The WLL system enables connectivity with the Public Switched Telephone (PSTN). It uses radio connectivity instead of wired cable
The microwave wireless links can be used to generate a Wireless Local Loop (WLL). It is a milestone in telecommunication era and exists between the central office (CO) and the individual residences near the CO.
In the developed countries, the copper or fiber optic cables are installed at homes, offices and businesses in buildings. However, in the developing countries it is difficult to install cables.
The wireless links can be deployed in a couple of hours.
In the WLL systems there are two concepts namely NWLL and BWLL.
NWLL (Narrowband WLL) is used to replace conventional telephone systems and BWLL (Broadband WLL) is used to produce higher speed data and voice services. Thus, WLL is the best system to handle high data traffic in the local loop systems.
The WLL systems are based on the Personal Communication systems (PCS) like mobile technologies like W-CDMA, GSM, PDC, etc.
The capacity requirement of WLL is different from that of the capacity need of fixed WLL system. In a fixed system the capacity is provided to meet subscribers of known numbers but it is no so in mobile wireless as it has to meet the traffic in worst cases.
WLL system must have features like:
They should provide better Quality of Service (QoS)
They should be compatible with other cellular technologies.
They should have complete scalability to meet the traffic requirements.
Advantages:
The cost of wireless equipment is less,once paid no additional costs are required whereas the fibre
optic and copper cables need to be leased from the service provider on monthly basis.
Wireless equipment's can be installed in a couple of hours.
They have good scale of installation.