WiMAX and WiMAX2 are microwave access technology standards used in mobile communication. Today the demand for broadband services is growing rapidly and only wired solution like Digital subscriber line (DSL), Ethernet, fiber optics are capable of full filling those needs. But it is extremely costly to provide the last mile connection using wired technologies and providing broadband to rural areas are not profitable, hence wireless solution is needed. The emergent need for the wireless loop is the high demand for Voice over IP, multimedia streaming, interactive gaming etc. so the IEEE 802.11 Wi-Fi networks are established to cater for the demand but their short range and lower bandwidth has restricted their capability and WiMAX (Worldwide Interoperability for Microwave Access) has emerged to fill the gap.
WiMAX
WiMAX (Worldwide Interoperability for Microwave Access) is one of technologies accepted for 4G networks specified by ITU. It is based on IEEE 802.16 standard and which is also known as wirelessMAN and main objective of the specifications is to become the wireless loop instead of cable related technologies for broadband access. Mobile WiMAX is the IEEE 802.16e and the current spectrum utilized for WiMAX spans from 2.3 GHz to 3.5 GHz. Multiple Access Technology being used is OFDMA (Orthogonal Frequency Division Multiple Access) with bandwidth varying from 1.25 MHz to 20 MHz based on the demand.
WiMAX either can give coverage up to 50 km or downlink speed of 70 Mbps at most and this inherent tradeoff between distance and coverage is the major limitation. The WiMAX architecture consists of three major components namely MSS (Mobile Service Station), ASN (Access Service Network) and CSN (Connectivity Service Network) as compared to GSM and 3G networks.
WiMAX2
This is the IEEE 802.16m standard and its implementation will be taken place in 2012 most probably. This new standard is backward compatible with the existing 802.16e standard (WiMAX) and as a result upgrade to new system is cost effective. The main goal behind the new standard is to provide downlink speed of more than 100 Mbps to users with lower latency and increased VoIP capacity. It is said that high data rates are achievable via smart antenna technology with multi channel approach. Spectrum utilization is below 6GHz and could operate on the range specified for IMT – advanced with bandwidth varying from 5MHz to 40 MHz depending on the demand.
Difference between WiMAX and WiMAX2 Network Technology
1. WiMAX downlink speeds are in the range of 100 Mbps whilst WiMAX2 aims at providing 300 Mbps for subscribers which is compatible with ITU specifications for 4G network technology.
2. WiMAX2 technology utilizes 4×2 MIMO antennas enabling signals everywhere so that the speed will be doubled as that of WiMAX.
3. WiMAX channel bandwidth is 20MHz and WiMAX2 bandwidth has doubled and varying bandwidth is used based on the traffic.
4. WiMAX is currently deployed in many countries and people use then daily and WiMAX2 will be expected to commercialize in between 2011 – 2012.