When Wi-Fi meets WiMAX

The combination of Wi-Fi and WiMAX could have as profound an effect on Internet usage as the ubiquitous GSM/CDMA networks had on voice communications, writes Chirasrota Jena.

Broadband over wireless will revolutionise the lives of people by giving them a high-speed connection directly to their colleagues, partners and family while delivering information to them anywhere at all. Wireless technologies such as 3G, Wi-Fi and WiMAX (Worldwide Interoperability for Microwave Access) will co-exist, working together to meet customer needs. No single broadband wireless technology will become dominant or ubiquitous.

The overall India WLAN equipment market has been growing at a healthy pace with a majority of the growth coming from the enterprise sector. Companies have realised the productivity benefits of providing mobility to their workforce. Over the last two years, the home segment has shown increased interest in creating a wireless network at home for using personal devices. This sector has huge potential, which is limited only by the poor broadband infrastructure in the country. The government has been pushing Wi-Fi from last year. As part of the broadband policy, Wi-Fi services will be de-licenced, which should hopefully lead to a hotspot explosion. Educational institutions were among the first to deploy WLANs in India. New deployments in coffee shops, hotels and airports are sprouting.

Informs Sunil Rao, Business Development Manager, Wireless, Cisco Systems India and SAARC, “From a standards point of view, 802.11b will lead due to the early adoption advantage that it holds. However, there is a shift towards 802.11g as vendors have stopped shipping 802.11b products. Of late, the hospitality industry has taken a keen interest in the technology.”

Technology to watch

WiMAX is an alternative to cable and DSL. It is the standard-based broadband wireless access technology for enabling the last mile delivery of information. WiMAX will provide fixed, nomadic, portable and (eventually) mobile wireless broadband connectivity without the need for a direct line-of-sight connectivity between a base station and a subscriber. In a typical cell radius deployment of three to 10 kilometres, WiMAX-certified systems can be expected to support capacity of up to 40 Mbps per channel for fixed and portable access applications. The key technologies that define WiMAX are IP, OFDMA (Orthogonal Frequency Division Multiple Access), QoS (Quality of Service) and MIMO. WiMAX based on the IEEE 802.16 standard is expected to enable true broadband speeds over wireless networks at a cost point that enables mass-market adoption.

Mobile WiMAX is based on OFDMA technology which has inherent advantages in throughput, latency, spectral efficiency and advanced antennae support, ultimately enabling it to provide higher performance than today’s wide area wireless technologies. Explains Surendra Arora, Director, South Asia, Customer Solutions Group, Intel, “There are two main applications of WiMAX—fixed WiMAX applications, which are point-to-multipoint enabling broadband access to homes and businesses, and mobile WiMAX which offers the full mobility of cellular networks at true speeds. Both the fixed and mobile applications of WiMAX are engineered to help deliver ubiquitous, high-throughput broadband wireless services at a low cost.” Approximately 60 percent of the WiMAX subscribers will be mobile customers who are predominantly residential, while fixed WiMAX will continue to be driven by large corporations, and to a lesser extent, by SMB customers.

Same tech, different applications

Wi-Fi and WiMAX are part of the same underlying technology, but with different applications. Wi-Fi provides seamless access within a small radius such as within a campus, whereas once WiMAX hits the market it will provide the ability to connect at speeds as high as 70 Mbps over a range of up to 48 km. Since WiMAX would be a fairly new technology it will be comparatively expensive, therefore it is safe to assume that both the technologies have a role to play in the Indian market. Many next-generation 4G wireless technologies may evolve towards OFDMA, and all IP-based networks are ideal for delivering cost-effective wireless data services.

According to Manish Gupta, Vice-president, Marketing & Alliance, Aperto Networks, “The latest trend in the wireless sphere is to use the two technologies (Wi-Fi and WiMAX) in a complementary fashion. Especially for mesh networks, network operators are discovering the benefits of using WiMAX to backhaul Wi-Fi mesh clusters (or in some cases hotspots), greatly decreasing network latency and increasing cost-effectiveness.” As Wi-Fi networks grow large enough to accommodate a neighbourhood or a city, the usability decreases due to the latency introduced with each new node. These networks also begin to get quite expensive due to the large number of nodes required. Introducing WiMAX into Wi-Fi mesh networks helps network planners smartly build large hot zones, backhauling traffic from heavily utilised hotspots versus covering large unused areas with Wi-Fi.

VoWiFi and WiMAX

Comments Rao, “The merger of Wi-Fi with VoIP (Voice over Internet Protocol) is an area that will see growth. VoWiFi (Voice over Wireless Fidelity) means a Wi-Fi-based VoIP service, or to put it in another way, a wireless VoIP system. While VoIP consists of the hardware and software that enable people to use the Internet as a transmission medium to make calls, VoWiFi is the wireless version of this technology that is designed to work on wireless devices such as a laptop or PDA. Along with the added benefits that it brings to businesses and to those with a need for wireless communication, VoWiFi opens up the door for a whole new market of consumer products such as a standalone VoWiFi handheld.”

The demand for broadband connectivity from urban homes and SMBs is growing rapidly, but this cannot be met effectively by existing wireline technologies. Wireless will be the dominant delivery mode for broadband services just as wireless now dominates voice services. Adds Gupta, “Thanks to its true broadband performance, early availability and cost advantages, WiMAX is best positioned to serve this huge Indian market. Several Indian service providers have already acquired suitable spectrum licences to deploy wireless broadband services, and are planning early roll-outs in 2006.”

Advantages and impediments

The presence of leading WiMAX technology vendors in India will for the first time usher significant local high-technology value-additions, while working with service providers also help fine-tune WiMAX deployment in the country. Explains Arora, “The most significant benefit of WiMAX compared to existing wireless technologies is the range. WiMAX has a communication range of up to 30 miles. This can cover over 2800 square miles, enough to blanket an entire city. The cost of servicing an end-user is much lower with WiMAX when you compare it to fibre or DSL, where there is no infrastructure today.”

But there are also impediments to WiMAX in India. Spectrum policy from the regulators in 3.3 GHz, 2.5 GHz or 700 MHz is unclear, as is licence policy. Then there are competing lobbies like CDMA. As Arora points out, “Expensive backhaul cost is a great impediment to WiMAX. Backhaul refers both to the connection from the AP back to the provider and to the connection from the provider to the core network. To extend wireless access nodes, providers still rely on wires for long-distance coverage. Some providers find wiring large areas too expensive.” Without QoS, applications such as VoIP may reduce a call’s quality, thus limiting the provider’s ability to tier services and obtain additional revenue streams. Current Wi-Fi last mile and large coverage solutions offer excellent data transfers.

The road to WiMAX

India is increasingly embracing wireless technologies. High-speed wireless broadband technology based on WiMAX promises an economically viable solution to accelerating Internet adoption. WiMAX has the potential to provide India with widespread Internet access that can usher in economic growth, better education and health care, and improved entertainment services as it has done elsewhere in the world. Intel is working within the wireless industry to drive the deployment of both Wi-Fi and WiMAX networks. The company is one of the founders of the WiMAX Forum, the industry-led, non-profit organisation formed to promote and certify the compatibility and inter-operability of broadband wireless products. In addition, Intel has help proliferate Wi-Fi adoption with its Centrino platform.

Aperto has at least six WiMAX clients in India, including VSNL, which recently completed the deployment of the company’s WiMAX-class PacketWAVE multi-service broadband wireless system in over 65 cities across India. This was part of an initial deployment phase with the goal of growing the network to cover over 200 cities within 12 months. Aperto’s PacketWAVE family of base stations and subscriber units is part of a countrywide network that enables high-speed wireless voice and data services for a wide variety of end-users throughout India. Informs Gupta, “Aperto has been working closely with VSNL since 2004, and has been involved in all phases of network design and deployment. VSNL has deployed hundreds of units of the PacketWAVE series of products in the 3.3 GHz-3.4 GHz band.” Aperto’s five other service provider customers in India have not been disclosed.

The global WiMAX market is growing at the rate of 30 percent per year, and is expected to touch $2.8 billion by 2009 from the present $ 600 million. Remarks Arora, “Intel is currently working with service providers and state governments to deploy wireless technologies in Ahmedabad, Bangalore, Chandigarh, Mumbai and Pune. The company is making custom-made PCs available at affordable prices. The bottom-line is to facilitate wireless broadband Internet access under a WiMAX environment. To offer wireless broadband connectivity at railway stations across India, Intel will work with Tata and VSNL in bringing Intel-based PC solutions and WiMAX broadband connectivity to Tata’s RailTel cyber cafes.”