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Wimax

In this article, we shall tell you all about WiMAX. Well, the term itself stands for Worldwide Interoperability for Microwave Access, and it is a kind of telecommunications technology that gives wireless transmission of data, by use of various transmission modes – from point-to-multipoint links to portable and fully mobile Internet access. One can get Broadband speeds up to 3Mbit / s, and there is no need for cables. This technology is basically based on the IEEE 802.16 standard, which is also called Broadband Wireless Access. So where does the term WiMAX come from? Well, it was created by the WiMAX Forum – this forum was formed in June 2001 for the promotion of interoperability and conformity of the standard. The forum itself says that WiMAX is a standards-based technology which allows the delivery of last mile wireless Broadband access, thus acting as an alternative to cable and DSL.

So what is WiMAX used for? Firstly, it can be used for connecting Wi-Fi hotspots to the Internet; it also provides a wireless alternative to DSL and cable for last mile Broadband access. Data and telecommunications services are provided, and WiMAX also provides a source of connectivity to the Internet, as part of a business continuity plan. This is only true if the business has both a fixed and a wireless Internet connection, from unrelated providers – then they are unlikely to be affected by the same service outage. Finally, another important use of WiMAX is that it gives portable connectivity quickly and efficiently.

WiMAX is now being evaluated by companies for last mile connectivity. This may result in lower prices for both business and home customers – and it will most certainly bring the availability of Broadband to places where it has previously not been economically possible. In fact, after the tsunami in December 2004, WiMAX access was used for assisting in communications in Aceh, Indonesia. This was helpful because all other communication infrastructure had been wiped out – just the amateur radio was there, but could not effectively help the survivors communication with people who were outside the disaster area and vice versa. Thus, WiMAX was instrumental in helping people regenerate communication to and from Aceh, with its Broadband access.

Intel Corporation also donated WiMAX to help FEMA and FCC in the places that had been affected by Hurricane Katrina. Volunteers in the area used self-healing mesh, VoIP, and a satellite uplink with was combined with Wi-Fi on the local link.

Many manufacturers offer WiMAX subscriber unites in both indoor and outdoor versions. Usually, the self-install indoor units are more convenient, but there are often radio losses, which mean that the subscriber should be much closer to the WiMAX base station than with the professionally-installed external units. Plus, one must also take into account the fact that indoor-installed units need a substantially higher infrastructure investment, and there is also the operational cost, which includes site lease, backhaul, maintenance, etc – due to the high number of base stations needed to cover a given area. The size of indoor units is comparable to a DSL modem or a cable modem. The outdoor units, on the other hand, are usually the size of a laptop PC, and one may compare their installation process to the installation process of a residential satellite dish.

Mobile WiMAX has much potential, and thus now people are focusing on portable units. This includes handsets, which are similar to cellular smart phones, PC peripherals like USB dongles and PC cards, and embedded devices in laptops – which are now available for the Wi-Fi services. Plus, now there is also emphasis on the part of operators on consumer electronics like MP3 players, gaming consoles, and other such devices. WiMAX is actually more similar to Wi-Fi than to 3G cellular technologies – you should make note of this.

The WiMAX Forum website offers a list of the devices which are currently certified. However, this is not a complete list, as certain modules are embedded into MIDs (Mobile Internet Devices), laptops, and private labeled devices.

Many people are saying that WiMAX could be a possible replacement for cellular phone technologies like CDMA or GSM, and it could even be used as an overlay to increase capacity. WiMAX, in fact, has been considered as a wireless backhaul technology for 2G, 3G, and 4G networks, not only in developed nations, but also in poor nations.

One possible challenge of WiMAX is that deploying it in rural areas (which have limited or no Internet backbone) will definitely be difficult. Additional methods and hardware will be needed to get sufficient bandwidth from the nearest sources – the difficulty will be in proportion to the distance between the end-user and the nearest sufficient Internet backbone.

Just like the term Wi-Fi is used for interoperable implementations of the IEEE 802.11 Wireless LAN standard, WiMAX is a term that describes standard, interoperable implementations of IEEE 802.16 wireless networks. But it should be noted that there are major differences in the working of Wi-Fi and WiMAX.

An architecture has been proposed by the WiMAX Forum that defines how a WiMAX network should be connected with an IP based core network – which is usually chosen by operators that serve as Internet Service Providers (ISP). However, the WiMAX BS provides seamless integration capabilities with other types of architectures as with packet switched Mobile Networks. A number of components, and some of the interconnections (or reference points) between these, labeled R1 to R5 and R8, have been defined by the WiMAX Forum’s proposal. These are as follows – SS / MS: the Subscriber Station / Mobile Station, ASN: the Access Service Network, BS: Base Station, part of the ASN, ASN-GW: ASN gateway, part of the ASN, CSN: Connectivity Service Network, HA: Home Agent part of the CSN, AAA: Authentication, Authorization and Accounting Server, part of the CSN, and NSP: Network Service Provider.

One should take into account the fact that the functional architecture can be designed into many hardware configurations and not necessarily fixed configurations. For example, the architecture is more or less flexible enough to allow remote / mobile stations of varying scale and functionality, and Base Stations of different sizes – e.g. – femto, pico, and mini BS and also macros.