WiMAX systems
WiMAX (World Interoperability for Microwave Access) is a technology based on IEEE 802.16 and ETSI HiperMAN standards. The standards have been developed for broadband radio access in wide areas. They define device parameters and systems to ensure interoperability of the equipment coming from different manufacturers.
The basic advantage of the WiMAX systems is their broadband character, which allows delivery of IP services to the end subscriber that is a few dozen kilometers away from the base station. Wireless technology and available wide bandwidth reduce the network deployment costs and make possible a very fast deployment of the system and the provision of the services to subscribers. WiMAX systems are good supplement of ATM/Eth/DOCSIS cable networks.
One can distinguish a few standards within WiMAX technology:
The maximum throughput of the WiMAX technology is approx. 75 Mb/s. It is a very good and competitive result even with cable acces methods. To obtain this value, the receiver-base station distance cannot exceed 10 km. Actual throughput obtained in Poland is 10 Mb/s only. However, WiMAX links can reach 50 km.
The basic advantage of the WiMAX systems is their broadband character, which allows delivery of IP services to the end subscriber that is a few dozen kilometers away from the base station. Wireless technology and available wide bandwidth reduce the network deployment costs and make possible a very fast deployment of the system and the provision of the services to subscribers. WiMAX systems are good supplement of ATM/Eth/DOCSIS cable networks.
One can distinguish a few standards within WiMAX technology:
- IEEE 802.16d - frequency range from 2 to 11 GHz (in Poland from 3,6 GHz to 3,8 GHz), is a complement of the 802.16a standard (the first version of the WiMAX standard). It has been enriched by the NLOS functionality (there is no direct path between antennas), antenna separation functionality and sub-channalization feature. The standard was approved in 2004. However, it does not describe the mobile access.
- IEEE 802.16e - the latest standard introduced in mid-2007. The standard is still being developed towards access mobility (up to 60 km/h). The assymetric device is being designed for palmtops, laptops or mobile phones. The mobile version of WiMAX is called WiBro and is available now only in South Korea. Both standards use frequency channels in a different way. In IEEE 802.16d there are systems working on 2 channels - FDD (one uplink and one downlink) and systems with one channel - TDD. The IEEE 802.16e standard uses only one channel for uplink and downlink - TDD.
The maximum throughput of the WiMAX technology is approx. 75 Mb/s. It is a very good and competitive result even with cable acces methods. To obtain this value, the receiver-base station distance cannot exceed 10 km. Actual throughput obtained in Poland is 10 Mb/s only. However, WiMAX links can reach 50 km.
System scheme
System elements
- A BASE STATION (ACCESS POINT)
- TRANSMITTING-RECEIVING ANTENNAS
- CUSTOMER TERMINALS LIKE LAPTOPS WITH WIFI MODULES, STATIONARY MODEMS OR PCMCIA CARDS
- ADDITIONAL ELEMENTS (E.G., POWERING)
