Wifi Technology Article

WiMAX and metrozones

Many WiMAX operators are at a crucial stage in planning or deploying WiMAX networks. Their wait to obtain the necessary spectrum licenses, to get the initial delivery of Mobile WiMAX products, or to select a vendor is either over or about to end. Finally they are ready to start rolling out their networks and test them in real-life environments, with paying subscribers, on loaded networks.

As operators have progressed through network planning or deployment, the hottest issues in the Radio Access Network (RAN) have become outdoor reach and indoor coverage. As subscribers start using their network, providing the high capacity density that new devices and applications require will be another key target.

These are recurring issues for all new wireless data technologies, as the underlying physics they need to overcome to get good coverage and capacity are the same. WiMAX is no exception, despite the fact that techniques like Orthogonal Frequency Division Multiple Access (OFDMA) and Multiple Input Multiple Output (MIMO) will enhance coverage and capacity.

In many ways, however, WiMAX network operators have to meet tough market requirements that impose unprecedented challenges for coverage and capacity.

WiMAX and mobile broadband in general promise ubiquitous coverage, access for any fixed or mobile device, and support for bandwidth-intensive applications such as video and audio streaming or mobile TV. Subscribers expect WiMAX to combine Wi-Fi’s data rates and GSM’s extensive coverage. Being able to provide this type of service is a tall order for any WiMAX operator.

Market requirements for mobile broadband operators include the following:

Indoor usage. In most cases, subscribers will access the network from indoor locations. This is the case both for fixed users (accessing the network from home or the office), and nomadic and mobile ones. Some WiMAX operators suggest that up to 80% of traffic is generated by indoor subscribers. Accustomed to cellular networks, subscribers will demand good indoor coverage and will expect that their WiMAX devices will work regardless of location. Mobile devices. With their smaller antennas and lower power, mobile devices typically use a bigger share of network resources than larger devices. This is especially true for indoor locations, where mobile devices often need to use a less spectrally efficient modulation than fixed devices. As mobile devices become commercially available and subscribers start using them, requirements for network capacity will grow quickly. High traffic levels from subscribers. Subscribers will expect to pay a flat monthly fee and be able to access the WiMAX network as they do with their current work or home broadband connection. In some cases, WiMAX will in fact replace this connection. Even nomadic and mobile users will often be heavier users than current cellular data users, as they will have data-centric and consumer electronic devices (e.g. multimedia players or game consoles) that will typically run applications that generate heavy network traffic. Furthermore, these subscribers may even use the WiMAX network at home or in the office where they have an alternative wireline broadband connection, simply because it is more convenient. Bandwidth-intensive applications. Increasingly subscribers will use their devices for a wide range of broadband applications that for the first time will be accessible everywhere. Some of these (video streaming or music downloads) will require WiMAX operators to increase their network capacity. Uplink requirements will grow as well, as subscribers will generate the content (e.g. photographs, movies) they upload to their favorite websites.

Extensive outdoor and indoor coverage are not optional features. Once demand starts to grow, high capacity will also be a requirement. Ubiquitous coverage and high throughput are central to the expectations of potential WiMAX users across markets worldwide. It is crucial for operators to make the appropriate coverage and capacity assumptions early on in planning the network as this may lead to a more cost-effective and easily scalable network.

The question facing WiMAX operators today is how to meet these demanding market requirements in a cost-effective, scalable way, adding infrastructure that is fully integrated within their currently deployed networks.