@ccess Over The Airwaves

By Team Digit Published Date
01 - Feb - 2006
| Last Updated
01 - Feb - 2006
@ccess Over The Airwaves
About a decade ago, we were awed at the climactic sequence in Mission Impossible (the original, not the sequel) in which a top-secret list is transmitted from a laptop on the London-Paris TGV-France's high-speed railway. Wireless Net access has certainly become more commonplace! Mobile data access is now increasingly seen as an efficiency enhancer by large and small businesses.

Take the example of a marketing executive of a large corporate. Apart from being e-mail enabled, he also needs to access the company intranet from various locations within the country or even abroad. Wi-Fi is one of the answers to such needs.

Wi-Fi And WiMax
Wi-Fi implements the Wireless LAN specifications detailed under section 802.11 by the IEEE. It envisaged the creation of areas from where one's computing device could access the Internet. However, Wi-Fi penetration in India is largely limited to offices, airports, five-star hotels, and in some cases, university campuses. A notable exception is Bangalore with its public Wi-Fi centres.

Handset Connectivity 
You don't necessarily need data cards to be mobile. You could always use a regular phone-to-laptop data cable, or Bluetooth, and connect via GPRS or CDMA.
GPRS (GSM's wireless data technology package) plans cost as little as Rs 150 per month in some post-paid schemes, going up to approximately Rs 600.
Though real-life speeds for GPRS are reported to be just 56 to 96 kbps, costs are generally not linked to usage time or data transfer, so this works fine for the casual surfer.
Most CDMA (Code Division Multiple Access) handsets have an inbuilt modem, so once it's connected to your laptop, you can dial up and get online. Some users have reported download speeds for CDMA handsets to be  about 120 kbps. 

Perhaps future implementations of WiMax will finally allow us to have real "anytime, anywhere" broadband  access. But what options do we have until that rosy picture materialises?

The Mobile Revolution
With the Government  delicensing some frequencies in the 2.4 GHz and 5.1 GHz range, the number of public access hot spots are set to mushroom. Meanwhile protocols such as WAP, GPRS, EDGE, and CDMA offer mobile access solutions.

Typically, we access the Internet over these technologies by connecting our phones to our desktops or laptops and dialling up. This can often be a frustrating experience-for example, what if your phone's battery goes dead in the middle of a browsing session? If your phone isn't Bluetooth-enabled, you've got to deal with a mess of cables. And do you really want your phone balancing precariously on your knee while you're in a train? 

Enter The Data Card
Slotted into the standard type II PCMCIA (Personal Computer Memory Card International Association) card slot in notebooks, data cards offer wireless connectivity over the mobile phone network. With a data card, your laptop can be used to make and receive voice calls and SMSes as well. In short, data cards function as modems while also mobile phone-enabling your laptop. They offer you the option of just clicking an icon on your Desktop to get connected.

Cost And Plan Charges
 One-time Cost Monthly Charge (Rs) Data Usage Cap 
AirTel 12,999 399
100 MB
1 GB
1.5 GB
Hutch 12,000 499  100 MB 
Reliance 6500 650
1 GB
1.5 GB
Tata Indicom 9995  700  1 GB 

At one point of time, data cards weren't an affordable option for most people. But that's changed. If there were an equivalent of Moore's law for hardware pricing, data cards would more than satisfy it. A card that cost about Rs 14,000 to 17,000 in June 2005 now costs about Rs 6,500. Data cards are available from Reliance Infocomm, Airtel, Tata Indicom and Hutch.

Data card vendors point out the cost advantage over Wi-Fi in hotels for the business traveller. But though data cards may lose miserably when it comes to speeds, there's just no competition when it comes to actual mobility. Wi-Fi and WiMax just don't have enough of a presence to compete with data cards.

In addition, service providers claim that data cards will free us from the problems associated with dial-up connections such as timeouts, blackouts and frequent disconnections.

Universal Mobile Telecommunications System represents an evolution in terms of capacity, data speeds and new service capabilities from second- generation mobile networks. Using W-CDMA radio access technology that builds on GSM, it provides a clear evolutionary path for more than 80 per cent of the world's wireless market to offer speeds of up to 2 Mbps, and all the benefits of broadband connectivity while on the move. The protocol was evolved by a global alliance of telecommunications standards bodies headquartered in France. 
CDMA vs. GSM Data Cards
As against the claimed speeds of 144 to 153 kbps for Tata Indicom and Reliance data cards, both of which use CDMA, Airtel customer support promises 247 kbps for its GSM/EDGE data card. Hutch, the other GSM player, claims just three times the speed of GPRS.

GPRS usually offers lower data bandwidth  when compared to CDMA's high-speed technology 1xRTT (short for single carrier radio transmission technology), which has the capability of providing Integrated Services Digital Network (ISDN)-like speeds of as much as 144 kbps. However, 1xRTT requires a dedicated connection to the network for data transfer, whereas GPRS sends packets, which is why data calls made on a GSM handset won't block out voice calls like they do on CDMA phones.

Also, data transmission over CDMA is traditionally considered more secure than GSM, which allows multiple users to share the same channel.

An official from a leading CDMA player wrote off the EDGE (Enhanced Data for Global Evolution) claim of 247 kbps by questioning the number of EDGE-enabled towers. In Mumbai, for example, he said, the speeds at, say Nariman Point and Vashi may differ widely when EDGE "falls back" to GPRS (See box EDGE To GPRS Fallback). CDMA, on the other hand, he said, promises a uniform pan-India experience. While admitting that speeds would be inversely proportional to the volume of traffic handled by a particular tower, he stated 70 kbps as the actual average speed one can get with a CDMA data card.

EDGE To GPRS Fallback 
An EDGE data card can offer high speed connectivity only within range of an EDGE tower. When the user moves into a neighbouring cell site that may not be EDGE-enabled, data access speeds "fall back" to GPRS levels. 

But GSM still has the advantage of global connectivity. Of the 36 countries and 49 networks that the Hutch data card offers GPRS roaming in, almost 18 are in the "Pre-Commercial" stage, which, according to the Hutch Web site, means one would not be charged for international roaming as of now.

The Next Step
Increased speeds will only come with 3G, which is yet to be rolled out in our country (see box 3G). In the US, EVDO (Evolution Data Only) and EVDV (Evolution Data Voice) 3G have offered real speeds of 180 to 300 kbps, with bursts of 500 kbps.

The GSM counterpart, EDGE, doesn't seem to be quite up to speed-100 to 130 kbps with bursts of 200 kbps. When Universal Mobile Telecommunications System (UMTS) succeeds GSM (see box UMTS), speeds of up to 2 Mbps are promised.

Is It For You?
From all we've talked about, you're probably not sure whether or not to opt for a data card. The main factor is convenience-freedom from cables, disconnections, and so on.

A group of multinational wireless communications companies have banded together to develop and promote high-bandwidth third-generation (3G) wireless technology. The group, which goes by the name of 3G.IP, includes AT&T Wireless Services (now merged with Cingular), British Telecom, Ericsson, Lucent, Nokia, Nortel, Telenor AS, and Telecom Italia Mobile.
Mobile telephony and the Internet converged to create third-generation mobile services. The first commercial 3G service was rolled out by DoCoMo in Japan in 2001.
3G services combine high-speed mobile access with Internet Protocol (IP)-based services. Technologies such as W-CDMA (wide-band CDMA), CDMA-2000 and TD-SCDMA are deployed to enable access to information, media and entertainment, anytime, anywhere.

Another issue is that of the price of the card itself: the table above (Cost And Plan Charges) should help you in your cost analysis.

Some also speculate that service providers might offer priority access to data card customers, since they would fall in the "business users" category.

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