Uses
The bandwidth and reach of WiMAX make it suitable for the following potential applications:
- Connecting Wi-Fi hotspots with each other and to other parts of the Internet.
- Providing a wireless alternative to cable and DSL for last mile (last km) broadband access.
- Providing high-speed data and telecommunications services.
- Providing a diverse source of Internet connectivity as part of a business continuity plan. That is, if a business has a fixed and a wireless internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage.
- Providing nomadic connectivity.
Broadband Access
Many companies are closely examining WiMAX for "last mile" connectivity at high data rates. This could result in lower pricing for both home and business customers as competition lowers prices.
In areas without pre-existing physical cable or telephone networks, WiMAX may be a viable alternative for broadband access that has been economically unavailable. Prior to WiMAX, many operators have been using proprietary fixed wireless technologies for broadband services.
Access of WiMAX had helped communication in Aceh, Indonesia, after the tsunami in December 2004. All communication infrastructures in the area were destroyed making the surviving people unable to communicate with people outside the disaster area and vice versa. WiMAX provided broadband access that helped regenerate communication to and from Aceh so that condition post-tsunami can be retrieved.
WiMAX subscriber units are available in both indoor and outdoor versions from several manufacturers. Self install indoor units are convenient, but the subscriber must be significantly closer to the WiMAX base station than with professionally installed units. As such, indoor installed units require a much higher infrastructure investment as well as operational cost (site lease, backhaul, maintenance) due to the high number of base stations required to cover a given area. Indoor units are comparable in size to a cable modem or DSL modem. Outdoor units allow for the subscriber to be much further away from the WiMAX base station, but usually require professional installation. Outdoor units are roughly the size of a textbook, and their installation is comparable to a residential satellite dish.
Limitations
A commonly held misconception is that WiMAX will deliver 70 Mbit/s, over 70 miles (112.6 kilometers) when the recipient is moving or mobile. Each of these is true individually, given ideal circumstances, but they are not simultaneously true. In practice this means that in line-of-sight environments you could deliver symmetrical speeds of 10Mbps at 10km but in urban environments it is more likely that 30% of installations may be non-line-of-sight and therefore users may only receive 10Mbps over 2km and if the recipient is on the move the bps rates drop significantly. WiMAX has some similarities to DSL in this respect, where one can either have high bandwidth or long reach, but not both simultaneously. The other feature to consider with WiMAX is that available bandwidth is shared between users in a given radio sector, so if there are many active users in a single sector, each will get reduced bandwidth. However, unlike SDSL where contention is very noticeable at a 5:1 ratio (if you are sharing your connection with a large media firm for example), WiMAX does not have this problem. Typically each cell has a whole 100Mbps backhaul so there is no contention here. In practice, many users will have a range of 2-, 4-, 6-, 8- or 10Mbps services and the bandwidth can be shared. If the network becomes busy the business model is more like GSM or UMTS than DSL. It is easy to predict capacity requirements as you add customers and additional radio cards can be added on the same sector to increase the capacity.
