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nt of wired solutions, For example, digging to support the trenching of cables is not needed. Operators do not have to submit further applications to the Government that have acquired licenses to use one of the licensed bands, or that wish to use one of the unlicensed bands. Once the installation of antenna and equipment is complete and they are powered, WiMAX is ready for service. In most cases, deployment of WiMAX network can be deployed with in hours, as compared to other solutions that take months for deployment.

Multi-Level Service
The QoS provisioning is generally based on the Service Level Agreement (SLA) among the service provider and the end-user.

Interoperability
WiMAX is based on international, vendor-neutral standards, which facilitate end-users to travel and use their SS at different locations, or with different service providers. Interoperability protects the initial investment of an operator as it can choose equipment from diverse equipment vendors, and it will prolong to bring the costs of equipment down as a result of mass adoption.

Portability
Like current cellular systems, once the WiMAX SS is powered up, it recognizes itself, finds out the characteristics of the link with the BS, provided that the SS is registered in the system database, and then its transmission characteristics are negotiated by it accordingly.

Mobility
To support mobility, key features have been added in IEEE 802.16e amendment. The OFDM and OFDMA physical layers have been improved to support devices and services in a mobile environment. The standard has hereditary OFDM's better NLOS (Non-Line Of Sight) performance and multipath-resistant operation, so it is highly appropriate for the mobile environment.

Cost-effective
The costs of the standard will drive down considerably due to mass adoption of the standard, and the use of low-cost, mass-produced chipsets, and the consequential competitive pricing will present significant cost savings for service providers and end-users.

Wider Coverage
Multiple modulation levels are supported by WiMAX including BPSK, QPSK, 16-QAM, and 64-QAM. WiMAX systems cover large geographic area when outfitted with a high-power amplifier and functioning with a low-level modulation (BPSK or QPSK) and when the path among the BS and the SS is unhindered.

High Capacity
End-users can be provided significant bandwidth by making use of higher modulation (64-QAM) and channel bandwidth from (1.25MHZ to 20 MHz).

3.7 USAGE SCENARIOS
WiMAX technology will modernize the way we communicate. The people who are highly mobile are provided freedom and will stay connected with voice, data and video services. The WiMAX standard addresses a large range of applications and usage scenarios which are grouped into two broad categories, private networks and public networks.

3.7.1 Private networks
Single organization, institution or business uses private networks to provide dedicated communication links for the secure and reliable transfer of voice, data and video. High priority is generally given to quick and easy deployment, and configurations are typically Point-to-Point or Point-to-Multipoint[21].

3.7.1.1 Cellular backhaul
The cellular services market is becoming progressively competitive. For cellular operators to stay in the busin