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Answered! Why is India's 3G connection so slow

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BANGALORE, INDIA: As promised, we are back with answers regarding why do we lag in terms of 3G speed in the country. Here are the answers to a few questions that we thought would be suitable in bringing out the concerns with regards to slow 3G networks.

Our experts for the story are: Stéphane Téral, principal analyst, mobile infrastructure and carrier economics, Infonetics Research and Ashim Roy, country manager, Stoke Networks India.

CIOL: Why is it that though service providers claim speeds such 7 mbps up to 21 mbps, whereas, it is not being delivered to an end consumer?

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Stéphane Téral: Announced or advertised download speeds usually are theoretical speeds that can never be attained, unless you are the only user attached to the base station! Basically, lots of factors come in to play and affect download speeds. The fundamental parameter is the number of users attached to a base station at a certain time, then how far the user is from the base station. Another factor is the spectrum allocation: how wide the channel or carrier is, because the wider it is, the better the throughput is.

Ashim Roy: 3G infrastructure is based on 3GPP standard. This standard has evolved over a period and the changes are tracked in the Release number. At a high level, 3GPP Release 5 standard uses 16QAM modulation and supports data rate of 7.2 Mbps at physical layer and Release 7 standard uses 64QAM modulation and supports data rate of 21.1 Mbps.

Actual data rate at the application layer is typically 80-85 per cent of the physical layer data rate. So, as soon as the operator upgrades to a specific release of 3GPP standard, they may claim that they support 7.2 Mbps or 21.1 Mbps or for that matter 337.5 Mbps (Release 11).

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Now, comes the fun part. Each cell tower supports data communication to/from many end user devices (e.g.cell phone, tablet etc.). Typically, cell towers are capable of supporting upwards of 250 simultaneous voice calls. Some are capable of supporting as many as 1,000 simultaneous voice calls. However, when it comes to data throughput, the main limitation is that of backhaul - interface to carry data to/ from cell tower to operator's network and finally to Internet.

Many of the recently deployed cell tower equipment support 100 Mbps backhaul throughput. So, it is theoretically possible that five subscribers may be able to get almost 21.1 Mbps (21.1 M * 5 = almost 100 M) simultaneously, if they are connected to this particular cell tower with 100 Mbps backhaul.

Of course, at this point no one else can make voice calls and no other subscriber can get data downloaded. In reality, there are other factors that will reduce the ability of a subscriber to experience 21.1 Mbps data throughput and that is because operators never allow all of the bandwidth being used by the data services. In fact, a major part of the revenue still comes from voice service and hence, bigger portion of the available bandwidth is reserved for voice rather than data.

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Moreover, 64QAM modulation is highly sensitive to signal quality, which depends upon distance between the cell tower and end user device and obstructions between cell tower and end user device (large buildings, trees, rain, snow etc). So, ideally operator may advertise that they can provide 21.1 Mbps data rate, but realistically most subscriber will not see any more than 2 Mbps for any sustained duration. Most common end user experience will be closer to 250 kbps data throughput.

CIOL: What needs to be done to improve the signal strength?

Ashim Roy: In order to improve data throughput at the end user device one must improve the signal quality at the end user device. One approach is deployment of more cell towers. Another approach is the deployment of micro/ pico cells, which are small towers covering a few buildings. A third approach is the deployment of femto cells that provide better signal quality within each home.

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Femto architecture uses DSL as the backhaul from home to overall network. All of these have different cost and regulatory implications. None are technical challenges at the present time.

CIOL: Are there any technical challenges involved in it?

Ashim Roy: I believe there are no technology challenges for achieving high speed 3G network deployment. The problems are all to do with regulation and business.

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Regulatory stance of the Government has to change. Unless the operators feel that Government is helping their cause and interested in relaxing licensing rules, it is unlikely that operators will be willing to invest more money to solve these problems.

CIOL: Why can't service providers plan tariff based on connection speed as well as usage and not just usage?

Ashim Roy: When a subscriber signs up for 3G service, they expect to get data rates as advertised by the operators - 3.1 Mbps, 7.2 Mbps or 21.1 Mbps etc. Currently, subscribers do not get anywhere near the advertised data rates.

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If the tariff is based on usage, the subscriber is able to track their data usage. However, tracking connection speed is well beyond the capability of most of the subscribers. If connection speed is used as a parameter in setting tariff, this will create a huge transparency concern among the subscribers.

CIOL: How can we make 3G a success in India?

Stéphane Téral: In order to make 3G an overall success in India, you need to have affordable smartphones and data plans. You also need to develop apps specific to the Indian market -- apps that can make their lives better or that matter to the Indian population -- for example, apps related to the game of Cricket. There are tons of little things that can change people's daily lives via apps.

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