According to abbreviationfinder, WiMAX stands for Worldwide Interoperability for Microwave Access, and is the mark that certifies that a product conforms to the ‘IEEE 802.16’ wireless access standards. These standards will allow connections at speeds similar to ADSL or cable modem, without cables, and up to a distance of 50-60 km. This new standard will be compatible with previous ones, such as Wi-Fi (IEEE 802.11). WiMAX technology will be the basis of metropolitan Internet access networks, will serve as support to facilitate connections in rural areas, and will be used in the business world to implement internal communications. In addition, its popularization will mean the definitive launch of other technologies, such as VoIP (voice calls over the IP protocol). To promote the use of WiMAX standards, it is necessary that manufacturers of electronic devices reach agreements to develop this technology, giving rise to to certifications that ensure the compatibility and interoperability of antennas, processors or receivers.
WiMAX Features
- Distances of up to 80 kilometers, with very directional and high gain antennas.
- Speeds of up to 75 Mbps, 35+35 Mbps, as long as the spectrum is completely clean.
- Facilities to add more channels, depending on the regulation of each country.
- Configurable and non-closed bandwidths, subject to spectrum ratio.
- It allows dividing the communication channel into small subcarriers (two types: guards and data).
WiMAX Evolution
- 16: Uses licensed spectrum in the range of 10 to 66 GHz, requires direct line of sight, with a capacity of up to 134 Mbps in cells from 2 to 5 miles. Support quality of service. Published in 2002.
- 16a: Extension of the 802.16 standard towards bands from 2 to 11 GHz, with NLOS and LOS systems, and PTP and PTMP protocol. Published in April 2003.
- 16c: Extension of the 802.16 standard to define features and specifications in the 10-66 GHz band. Released January 2003.
- 16d: Revision of 802.16 and 802.16a to add profiles approved by the WiMAX Forum. Approved as 802.16-2004 in June 2004 (The latest version of the standard).
- 16e: Extension of 802.16 that includes the nomadic Broadband connection for portable devices such as notebooks. Published December 2005. _
- 16m: An extension of 802.16 that promises data delivery at a theoretical speed of 1 GB.
There are currently two main types of WiMAX technology:
- Fixed WiMAX (802.16d- 2004) is a point-to-multipoint technology, while mobile WiMAX is a multipoint-to-multipoint technology that resembles that of a cellular infrastructure. These two solutions were designed to provide high-performance wireless Broadband services at reduced costs.
- Mobile WiMAX (802.16e- 2005), is based on OFDMA (orthogonal frequency division multiple access) technology that offers inherent advantages in terms of latency, efficiency in the use of the radio frequency spectrum and advanced antenna support, which which ultimately translates into superior performance compared to current wide-area wireless network technologies. On the other hand, next-generation 4G wireless technologies are evolving into OFMDA and IP networks as they are ideal for providing affordable wireless data services.
WiMAX Forum
The WiMAX Forum is an industry-driven, not-for-profit organization created to promote and certify the interoperability of wireless broadband products in accordance with the IEEE 802.16 and ETSI HiperMAN standards. The objective of this institution is to accelerate global implementations and expand the market for broadband wireless access solutions.interoperable and standards-based. The forum is working with member companies to develop standardized profiles and interoperable WiMAX products around specific bands of the radio frequency spectrum, primarily 2.3GHz, 2.5GHz, 3.5GHz and 5.8GHz. To date, more than 368 companies, including 136 service providers, are members of the WiMAX Forum.
Characteristic
The IEEE 802.16 standard refers to a BWA (Broadband Wireless Access) system with high data transmission rate and long range (up to 50-60km), scalable, and that allows working in both “licensed” and “unlicensed” spectrum bands. “. The service, both mobile and fixed, is provided using traditional sectoral antennas or adaptive antennas with flexible modulations that allow bandwidth to be exchanged for range.
Fixed WiMAX IEEE 802.16-2004
IEEE 802.16-2004 is a recent fixed wireless access technology, which means it is designed to serve as a replacement technology for wireless DSL, to compete with DSL or broadband cable providers, or to provide basic wireless access. voice and broadband in areas where no other access technology exists. 802.16-2004 is also a viable solution for wireless backhaul for Wi-Fi access points or potentially for cellular networks, particularly if licensed spectrum is used. In general, the CPE (User Equipment) consists of an outdoor unit , antenna, and a modem.indoor, which means a technician is required to get a residential or business subscriber connected to the network. In certain cases, a self-installing indoor unit can be used, in particular when the subscriber is relatively close to the transmitting base station. Also, self-installing CPEs should make the 802.16-2004would be more economically viable since a large part of the customer acquisition cost (CPE installation) is drastically reduced. Although it is technically possible to designate an 802.16-2004 data card, handheld devices with an embedded 802.16-2004 solution do not appear to be a top priority within the industry at this time. The fixed version of the WiMAX standard was approved in June 2004, although the interoperability test was in 2005
IEEE 802.16E Mobile WiMAX
Although the official publication of the 802.16-2004 standard laid the foundations for the initial deployment of the new wireless Broadband access technology, the final expectations of WiMAX go beyond being a wireless ADSL -type system for urban environments and rural. Actually, the promoters of this project pursue the ambitious goal of WiMAX being the wireless technology that unifies the world of mobile telephony and data networks. With this objective, in December 2002, the IEEE 802.16E Working Group was created to improve and optimize support for the combination of both fixed and mobile communication capabilities at frequencies below 6 GHz. carried out the official ratification of the new Mobile WiMAX standard (802.16E). The new version of the standard introduces the support of SOFDMA technology (a variation of the OFDMA modulation technique) which allows a variable number of carrier waves, which is added to the already existing OFDM and OFDMA modes. In addition, IEEE 802.16E offers enhanced support for Multiple Input Multiple Output (MIMO) technologies andAAS (Adaptive Antenna Systems). It also includes improvements to optimize power consumption for mobile devices and thereby reduce the size of the CPE (Customer Premise Equipment) modem, as well as extensive security features. Lastly, there are also the IEEE 802.16f and IEEE 802.16g working groups that deal with fixed and mobile operation management interfaces.
WiBRO
WiBRO (Wireless Broadband) is the Korean version of the recently released Mobile WiMAX (IEEE 802.16e) standard. Therefore, WiBRO systems are based on the 802.16-2004 / 802.16e standards and use the 2.3 GHz band to provide high-speed wireless voice and data communications. One of the main objectives of any new wireless technology is to optimize the use of the spectrum. In this line, WiBRO uses a single 9 MHz frequency band to transmit and receive information and shares it by time division TDD-Time Division Duplex, a very efficient technique for asymmetric traffic as corresponds to Internet access. They also use the technique OFDMA as its access technology that combines multiple spectrally overlapping carriers, but keeping the modulated signals orthogonal, so that there is no interference between them and minimizing multipath interference. In addition, it supports various QPSK, 16QAM, 64QAM modulation schemes and an adaptive modulation system to improve communication efficiency. The technology also includes QoS quality of service.
Fixed WiMAX vs Mobile WiMAX
According to a report published by Juniper Research, the market for WiMAX equipment based on the 802.16d standard (fixed version) will be stagnated by the appearance of the corresponding mobile version (802.16e). In fact, the first mobile WiMAX certified products are expected in 2007. Compared to the fixed version, 802.16e is a superior standard, with huge added value in mobility, and also offers a fixed connection option. According to forecasts, mobile WiMAX will triumph at the user level, while the fixed version will be relegated to backhaul connections (for example, to transport Wi-Fi signals from hotspots
WiMAX applications
The first products will be outdoor units that will work in applications with or without line of sight between equipment, offering limited bandwidth and no mobility. Equipment will need to be installed in each home in order to use WiMAX. At this first moment, the same benefits of basic Internet access will be available. The second generation will be indoor, self-installing modems similar to cable or DSL modems. At that point, WiMAX networks will offer mobility for customers to take their laptop or WiMAX MODEM anywhere with coverage.
