June 8, 2009

Metro WiFi: Are You A Believer?

Frankly speaking, No, not I am.

Metro WiFi is the concept of turning an entire city or part of a city into a Wireless Access Zone. This is usually done by providing broadband via WiFi to large parts or all of a municipal area by deploying a wireless mesh network. The typical deployment design uses hundreds of routers deployed outdoors, often on utility poles. The operator of the network acts as a wireless internet service provider.

Metro WiFi was started as a bright idea, but soon the spark has faded. The idea was simple. People had already demonstrated their willingness to pay for broadband internet access at homes and offices. They were apparently falling in love with all things wireless. WiFi hotspots were sprouting up, even if they were mainly confined to coffee shops, airports and hotels.

WiFi allows local area networks (LANs) to be deployed without wires for client devices. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs. Wireless network adapters are now built into most laptops. The price of chipsets for WiFi continues to drop, making it an economical networking option included in even more devices.

Metro WiFi, thus highly anticipated by Wireless ISPs as well as by the consumers in last few years. As a result, few service providers invested in such projects with high hope. But something hasn’t quite gone according to plan. Evidence started to emerge that in many cases expectations were simply too high from WiFi. Soon, operators started to face technical and financial difficulties. Here are some few:

* WiFi networks have limited range. A typical WiFi home router using 802.11b or 802.11g with a stock antenna might have a range of 32 m (120 ft) indoors and 95 m (300 ft) outdoors. The new IEEE 802.11n however,
can exceed that range by more than double. Range also varies with frequency band. WiFi in the 2.4 GHz frequency block has slightly better range than WiFi in the 5 GHz frequency block. But still the range is too low for a City wide WiFi Coverage. As a result number of required WiFi access point is unrealistic.

* WiFi transmissions take place primarily within the 2.4 GHz spectrum, making them susceptible to interference from other wireless products operating in same frequency range. 2.4 GHz is universally accepted free spectrum. As a result, many Point to Point and Point to Multipoint radios are already deployed. In capital Dhaka, the number may cross more than thousands. Interference is already there and it is impractical to find any free channel in the range.

* Interference also may happen from Bluetooth® wireless enabled devices, cordless telephones, microwave ovens, baby monitors, and other household devices.

* Due to the complex nature of Radio propagation at typical WiFi frequencies, particularly the effects of signal reflection of trees and buildings, WiFi signal strength can only be predicted generally for any given area in relation to a transmitter. There are large numbers of high rise buildings in Dhaka. The city is so congested that even Mobile operators failed to provide sufficient signal quality in 900/1800 MHz. As we know lower the frequency, better the penetration, it is quite impossible for WiFi to penetrate in 2.4 GHz with much low power.

* Metro WiFi demands Access point to be deployed in low height. So it is advisable to install them in street lamp posts. But in Dhaka, lamp posts are not secured. At the same time, electricity problem is always there.

* WiFi performance decreases roughly as distance increases at constant radiation levels. At the same time, even with 50 – 60 % signal strength, performance level is below satisfactory.

* Because of the very limited practical range of WiFi, mobile use of WiFi over wider ranges is limited to move.

* The maximum amount of power that a WiFi device can transmit is limited by local regulations.

* The most common wireless encryption standard, Wired Equivalent Privacy or WEP, has been shown to be easily breakable even when correctly configured.

* Even the fastest current WiFi standards are pushed beyond their limit when trying to handle some of today's high end media. High-definition audio and video files are bandwidth and timely-delivery-intensive, and typical wireless networks have neither the transfer speeds nor the consistency to transfer them flawlessly. This problem is further compounded if there are multiple devices connected to the same access point because the bandwidth must be divided between all of the equipment.

* When emerging technologies like WiMAX, 3G or LTE is knocking at the door, WiFi, I found to be too backdated to compete with them. Realistically, WiFi is no match with them in terms of network coverage or capacity.

* Moreover, the infrastructure cost for deploying a Metro WiFi is not realistic compare to rate of return. Hundreds of Access points require to cover a small city like Dhaka but such deployment is not financially viable.

According to me, WiFi technology is absolutely fine for Indoor or Hotspot use. In a home or office environment, it is obvious that nobody wants to go for the hazard of wired systems. WiFi provided us the opportunity to eliminate this problem. But for wide area network WiFi is not suitable. The technology itself does not provide us that flexibility. So, better to keep with what it suites the best, that is for indoor use.

Now the same question again. Are you still the Metro WiFi believer?

3 comments:

Wireless Internet Provider Monitor said...

I am a believer in Metro WiFi. We know that it can be done and that we have the technology. But it can only happen if the government or a big business in the area is willing to take on this project.

MAMUN said...

I am a believer in Metro WiFi. But not possible in Dhaka

IT Connect Ltd. said...

iConnect has deployed the largest WiFi HotZone in South Asia. We would appreciate it we are included in your Tagzone.
www.ITConnectbd.com

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