Tuesday, February 22, 2011

Coexistence of Wifi & Femto Cells

What is Femto Cell:
Femto Cell is a small cellular base station, typically designed for use in a home or small business. It connects to the service provider’s network via broadband (such as DSL or cable). Lots of people face “low bar” problem in cell phones. This is due to reduced coverage in certain part of your home or even the whole area. Femto cells solves this problem by putting a cell base station at your location. Current designs typically support 2 to 4 active mobile phones in a residential setting, and 8 to 16 active mobile phones in enterprise settings. A femtocell allows service providers to extend service coverage indoors, especially where access would otherwise be limited or unavailable. Although much attention is focused on WCDMA, the concept is applicable to all standards, including GSM, CDMA2000, TD-SCDMA, WiMAX and LTE solutions.


Femto cells have been around for a while and finally the roll out is slowly picking up as Wireless Wifi connectivity is starting to slow down the traction of 3G/ 4G broadband services. Some people may yet debate the value of femtocells, but the tide has turned: in 2010, the number of femtocells around the world exceeded the number of macrocells, according to the Femto Forum.

Femtocells are small base stations that operators place in homes or businesses to improve coverage and capacity for users. While there is some debate yet about whether femtocells or Wi-Fi represents a better choice, most experts are now saying that the two technologies will work together.


AT&T has been rolling out Femto Cells in selective markets but with only voice services.Users can carry their femto cells if they travel anywhere. And if they leave their femto cells behind, they will be picked up by nearby cell towers/ BTS. But more and more service providers are starting to integrate Wi-Fi and Voice services in same base station so that end users can attach to the Wi-Fi network for data services and use the cellular connection for voice. Ubiquisys is one company that introduced new femtocells that include Wi-Fi during the conference.

It makes lots of economical sense to have femto for voice & Wifi for data services. But greedy network operators want to burden consumers with higher service charges in US, so roll out has been slow. Greed has often plagued telecoms & now celcomms for advancements in technology at even faster pace. That’s why open operating systems such as Android will open up the markets for increased competition, as web browsers did for Internet. Before I digress too much, Wifi is extremely important to bridge existing network infrastructure to voice networks and shatter Comms monopoly for consumers. Though Wifi offers cheaper existing Access Points (modems), Femto cells will burden consumers with additional cost of “yet another equipment” to buy or replace. Within 3G, consumers have been really unhappy over broadband requirements with Wimax or HSPA so far in 5MHz spectrum. Femto/Wifi combo can rescue carriers of shame.

Toward the end of last year, the number of femtocells in the U.S. reached 350,000, surpassing for the first time the number of macrocells. Globally, there are 1.7 million femtocells in use compared to 1.2 million macrocells.

The timing is right for even more growth of femtocells because many operators are upgrading their networks to LTE, the next generation mobile technology. At the same time they realize that users want to consume an increasing amount of data. Femtocells can help increase capacity for operators but deploying femtocells requires radio frequency planning. It's easier for operators to plan femtocells into new networks than it is to add them to an existing network.

Femto Cells also will break the trend of heavy leverage on LTE infrastructure & LTE Femtocells could roll out much sooner than previous generations. NTT DoCoMo is one operator that has been outspoken about working femtocells into its network upgrade plans, he said.

Femtocells can also help operators that are struggling with finding new sites for their base stations, an often expensive exercise. Femtocells are physically much smaller than a base station so can hang in many more kinds of locations. But at same time, Femtocells could encourage entrepreneurs to define new business models while breaking “Big Boys” operators.

Still, for some operators, sticking with Wi-Fi instead of femtocells makes sense. T-Mobile late last year said many of its Android phones would ship with software that allows people to use Wi-Fi to make phone calls and send SMS and MMS messages. Users can make Skype or Google phone calls using Wifi instead of using up their cell talk minutes. That offloads traffic from T-Mobile's cellular network and shifts the expense of backhaul to the Wi-Fi network.

The downside to using Wi-Fi currently is that users still have to actively turn on Wi-Fi on their phones before using it. But both Kineto and Ruckus talked about work going on internally and in standards bodies to make roaming between the cellular and Wi-Fi networks automatic. The confusion & technology use chunkiness will make these technologies harder for consumers to adapt.

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