IEEE 802.16: Broadband Wireless MAN Standard (WiMAX)

IEEE 802.16: Broadband Wireless MAN Standard (WiMAX)


An 802.16 wireless service provides a communications path between a subscriber site and a core network such as the public telephone network and the Internet. This wireless broadband access standard provides the missing link for the "last mile" connection in metropolitan area networks where DSL, Cable and other broadband access methods are not available or too expensive. The Wireless MAN technology is also branded as WiMAX.

IEEE 802.16 standards are concerned with the air interface between a subscriber's transceiver station and a base transceiver station. IEEE 802.16 is approved by th IEEE in June 2004. Three working groups have been chartered to produce standards: Task Group 1 of IEEE 802.16 developed a point-to-multipoint broadband wireless access standard for systems in the frequency range 10-66 GHz. The standard covers both the Media Access Control (MAC) and the physical (PHY) layers. Task groups a and b are jointly producing an amendment to extend the specification to cover both the licensed and unlicensed bands in the 2-11 GHz range.

IEEE 802.16 and WiMAX are designed as a complimentary technology to Wi-Fi and Bluetooth. The following table provides a quick comparison of 802.16a with to 802.11b:

Parameters	802.16a (WiMAX)	802.11 (WLAN)	802.15 (Bluetooth)
Frequency Band	2-11GHz	2.4GHz	Varies
Range	~31 miles	~100 meters	~10meters
Data transfer rate	70 Mbps	11 Mbps 55 Mbps	20Kbps 55 Mbps
Number of users	Thousands	Dozens	Dozens

WPAN: Wireless Personal Area Network Communication Technologies

Wireless Personal-Area Network (WPAN) is a personal area network using wireless connections. WPAN is used for communication among devices such as telephones, computer and its accessories, as well as personal digital assistants, within a short range.

The reach of a PAN is typically within 10 meters. Technologies enabling WPAN include Bluetooth, ZigBee, Ultra-wideband(UWB), IrDA, HomeRF, etc., in which the Bluetooth is the most widely used technology for the WPAN communication.

Each technology is optimized for specific usage, applications, or domains. Although in some respects, certain technologies might be viewed as competing in the WPAN space, but they are often complementary to each other.

The IEEE 802.15 Working Groups is the organization to define the WPAN technologies. In addition to the 802.15.1 based on the Bluetooth technology, IEEE proposed two additional categories of WPAN in 802.15: the low rate 802.15.4 (TG4, also known as ZigBee) and the high rate 802.15.3 (TG3, also known as Ultra-wideband or UWB). The TG4 ZigBee provides data speeds of 20 Kbps or 250 Kbps, for home control type of low power and low cost solutions. The TG3 UWB supports data speeds ranging from 20 Mbps to 1Gbps, for multi-media applications.

In the following table, the main characters of the WPAN technologies as specified in the IEEE 802.15 are compared:

Parameters	Bluetooth (IEEE 802.15.1)	UWB (IEEE 802.15.3)	ZigBee (IEEE 802.15.4)
Applications	Computer and accessory devices Computer to compute Computer with other digital devices	Multimedia content transfer, High-resolution radar, Ground-penetrating radar, Wireless sensor network, Radio locations systems	Home control Building automation Industrial automation Home security Medical monitoring
Frequency Band:	2.4 - 2.48GHz	3.1-10.6GHz	868MHz 902-928MHz 2.4-2.48GHZ
Range	~10 meters	~10 meters	~100 meters
Maximum Data transfer rate:	3 Mbps	1 Gbps	20 Kbps 40 Kbps 250 Kbps
Modulation	GFSK, 2PSK, DQSP, 8PSK	OPSK, BPSK	BPSK (868/928MHz) OPSK (2.4GHz)

WPAN, WLAN and WMAN technologies are complementary to each other and each play a unique role in today’s wireless communications. The following table outlines the three technologies:

Parameters	WMAN (IEEE 802.16 WiMAX)	WLAN (IEEE802.11)	WPAN (IEEE802.15)
Frequency Band:	2-66GHz	2.4 -5.8GHz	868 -10.6GHz
Range	~31 miles	~100 meters	~10meters (Bluetooth and UWB) ~100 meters (ZigBee)
Maximum data transfer rate:	134 Mbps	55 Mbps	1Gbps
Number of users:	Thousands	Dozens	Dozens

Comparison of WLAN, WPAN and WMAN Technologies

There are three main wireless technology groups for the fixed wireless communications, namely, Wireless LAN (or Wi-Fi), Wireless Personal Area Networking (WPAN) and Wireless Metropolitan Area Networking (or WiMax). While competing in many applications, each technology has its own application focus and limitations.

The key parameters of WLAN, WPAN and WMAN(WiMax) technologies are compared and displayed in the table below:

Technology	WLAN (IEEE)
Standard	802.11 Legacy	802.11a	802.11b	802.11g	802.11n
Release year	1997	1999	1999	2003	2008
Frequency Band	2.4GHz	5.8GHz	2.4GHz	2.4GHz	2.4 – 5.8GHz
Maximum Range	~70 meters	~100 meters	~100 meters	~110 meters	~160 meters
Maximum data rate	2Mbps	54Mbps	11Mbps	54Mbps	248Mbps
Number of users	Dozens	Dozens	Dozens	Dozens	Dozens
Access Method	DSSS, FHSS	OFDM	DSSS, CCK	OFDM	MIMO
Modulation Method	GFSK, BPSK, DBPSK, DQPSK	BPSK, QPSK, 16-QAM, 64-QAM	DPSK, DBPSK, DQPSK	BPSK, QPSK, 16-QAM, 64-QAM and DBPSK, DQPSK	BPSK, QPSK, 16-QAM, 64-QAM

Technology	WPAN (IEEE)				WMAN WiMAX (IEEE)
Standard	802.15.1 (Bluetooth)	802.15.3 (UWB)	802.15.3a (WiMedia)	ZigBee 802.15.4-2003 802.15.4-2006	802.16-2004 (802.116d) 802.16e-2005 (802.16e)
Release year	2002	2003	*	2003 and 2006	2004 and 2005
Frequency Band	2.4Ghz	3.1 to 10.6 GHz	2.4GHz	868 MHz, 915 MHz, 2.4 GHz	2-66GHz
Maximum Range	~10meters	~10meters	~10meters	~100 meters	~50 km
Maximum data rate	3Mbps	55Mbps – 1Gbps	110Mbps – 1Gbps	250 Kbps	134 Mbps
Number of users	Dozens	Dozens	Dozens	Dozens	Thousands
Access Method	FHSS	DS-UWB, OFDM	MB-OFDM	DSSS	MIMO-SOFDMA
Modulation Method	GFSK, 2PSK, DQSP, 8PSK	OPSK, BPSK, OOK, PAM, PPM, Bi-Phase	QPSK, DCM	BPSK (868/928MHz) OPSK (2.4GHz)	QPSK, QAM