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How to Set Up: A Wireless Network

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VoicenData Bureau
New Update

Maj. Gen. L Tahiliani, AVSM, VSM (Retd) Is head, India Operations, P-ComThere

are nearly 225 million people on the Internet. So much so, that

the Net is no longer a novelty. There is shopping on the Net,

doctors for consultation, and experts to guide you in your

investments. The Net, in short is a triumph of technology–a

digital revolution that has been more profound than a mere

application of hi-tech tools. It is also not just a reality; it

is a prelude to openness and free communications. Today, the

radio is a major component in the phenomenal growth of global

telecommunications. US has had a head start in this phenomenal

growth. In India, the Internet is still in its infancy. Among

the many reasons is the lack of infrastructure particularly in

the "last mile" connectivity. Those of us who have

used the Net through a dial-up connection will admit that it is

woefully slow and prone to frequent disconnection.

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Indian

Scenario

Intel

has predicted that in five years from now, all companies

will be Internet companies and those that are not will not

be companies. E-business/commerce will grow manifold.

Realizing this the Government of India (GOI) has

liberalized provision of Internet services and issued

licences to over 120 private companies. Unfortunately, the

growth has not been in the same proportion. The reasons

again are the problems of "last mile"

connectivity. Private ISPs cannot lay their own cables and

per force have to depend on the existing copper cable,

which is old and not suitable for high-speed data

connectivity. Realizing this, VSNL and STPI started using

point-to-point radio in the ISM Band for "last

mile" connectivity. The growth of our software

industry from $300 million a few years ago to $5 billion

bears testimony to what good connectivity can do for

business!

So what is holding up

other ISPs from using a similar approach? Perhaps, cost and

availability of the frequency spectrum. While software houses

and big corporates can afford spending a few lakh rupees,

smaller companies and private individuals cannot. However,

with the maturing of Point-to-Multipoint (PMP) radio

technology, the cost of equipment at the customer premises (CPE)

is fast decreasing. On volume sales the manufacturers would be

willing to offer hefty discounts, and with the GoI’s

co-operation in rationalizing import duties, the CPE can be

brought down to well below one lakh. This cost could again be

amortized over a few years, thus making it viable even for a

private individual. The procedure for obtaining WPC clearance

also could be further simplified. Step#1:

Know the Technology

PMP

system consists of a central hub with several remotes. Depending

upon the manufacturer, the number of remotes varies from 100 to

150. Such PMP systems are now available in the market resulting

in 50 percent saving on hardware costs and the spectrum usage.

Brief description of a Low-Capacity and a Broadband System is

being given.

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Low-Capacity

Systems: Such systems have been developed generally in the ISM

band for licence-free use in many countries. The hub-capacity

bandwidth varies from 256 Kbps-2Mbps and can service

approximately 120 remotes. Such a system uses a polling software

so that at any instant only one remote is addressed (TDM) thus

making available to that remote the entire hub-capacity

bandwidth. To the end customer, therefore, there is no bandwidth

limitation. The customer could be a single workstation or a LAN.

In case the customer is willing to pay only for a limited

bandwidth, e.g. 64 Kbps, this can be ensured through the use of

a bandwidth shaper. The range of communications is based on Line

of Sight (LoS) and could extend up to 40 kilometres. A number of

hubs could be co-located.

Broadband System:

Conceptually the system is akin to the Low-Capacity System.

However, here the bandwidth available at a remote could vary

from 64 Kbps — 40 Mbps. The total hub capacity could be as

much as 4 Gbps based on the number of sectors activated. There

is no restriction on the number of remotes as long as the sector

capacity of 200 Mbps is not exceeded. Because of the large

bandwidth involved such systems are generally available in the

frequencies of 10 Ghz and above. The available range of

communication depends on the frequency and the modulation scheme

but typically would be about 10-12 kilometres at 10 Ghz using

QPSK modulation. Depending upon the concentration of customers

more than one hub can be set up at a location using different

frequency channels available.

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Step#2:

Compare the Cost Options

It

is difficult to compare two different things. Nonetheless, it is

always better to consider the cost-benefit aspect before setting

up wireless network. Assuming that up-linking costs are similar,

comparison is restricted to the access network.

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Dial-Up

Internet Connectivity

Telephone

call charges @ Rs 25 per hour. For one year Rs 72,000 @ 10 hrs.

per day and 25 days a month excluding rentals for the telephone.

Leased-line

Connectivity

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As

on date, the DoT is only able to provide a 64 Kbps

leased-circuit or 2 Mbps leased-circuit. Since the wireless

solution offers all speeds, comparison is possible only at

speeds offered by DoT. The leased-line charges of 64 Kbps for a

distance of 25 kilometres are nearly Rs 29,000 per annum. This

amount has to be paid every year. Experience has, however, shown

that a large number of customers are veering round to obtaining

a wireless connectivity because of the low-reliability of such

lines and poor throughput. Wireless

Connectivity

Broadband

System:
Cost of the smallest configuration of a single

sector hub station with a 360 degree coverage having a capacity

of 200 Mbps with 50 remotes of varying capacities would be

approximately $10,00,000. In this case the remote is located on

top of a multi-storied building having corporate offices. The

distribution within the building is by structured cabling. With

each E1 giving 30 x 64 Kbps connections the cost per connection

is only Rs 13,000 (Assuming a multiplication factor of Rs 70 to

a $ to cater for CIF custom duties and so on. 7,00,00,000/200 x

30 = 11666 plus cost of cabling). There would be times when a

customer may want N x 64 Kbps, which is possible in this case.

If customs duty exemption is obtained under

"infrastructure", the cost would be considerably

lower. To this would have to be added certain overheads for

provision of service. Progressively as the hub capacity is

increased, the cost per connection would decrease substantially.

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Low-Capacity System: This

is suitable for areas where the corporates are scattered over a

geographical area. The Low-Capacity System could also be used to

provide extensions from a Broadband System to customers who are

located far way.

It could also be used to

provide "last mile" connectivity between the customer

and RAS. Since each remote in the Low- Capacity has a bandwidth

of N x 64 Kbps, extensions to many customers can be given

through structured cabling in a building, further making it even

more cost-effective. The landed cost of remote would be

approximately a lakh, which if amortized over a 4-year period,

would enable an ISP to provide the service at very competitive

rates.

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Step#3:

Obtain Clearance for Import Licence

The

law of the land requires an import licence for import of any

radio equipment. The Wireless Planning & Coordination (WPC)

wing provides this for a nominal fee. Without this licence, the

importer would not be able to get his consignment cleared from

the customs.

Step#4:

Request for the Use of Radio

The

next step is to put in a request for using the radio. The

request is made on a standard form available at the WPC. Details

such as name of the applicant, place to/form where the

communication is to be established, type of emission, frequency,

and so on are to be filled in. On receipt of such an

application, the WPC issues a Letter of Intent (LOI) for award

of license. Step#5:

Obtain the SACFA Clearance



Advantages of Wireless Connectivity for Internet

From the service provider’s view, the biggest advantage is that it can be set up very easily. It does not take more than a couple of hours to install a radio at the customer premises. Secondly, the ISP need not have a large number of lines at his RAS. The customer is permanently logged in and does not have to use his telephone connection. In other words he is provided a 24-hour connectivity at a 99.99 percent uptime. 

The

last and the final step is to obtain the clearance from Standing

Advisory Committee on Frequency Allocation (SACFA). Copy of the

application is sent to a large number of addressees for their

comments. The national airport authorities also play an

important role to ensure that the mast/tower to be constructed

does not affect flight safety. The entire procedure many take up

to 3 months. If appears complicated and long drawn but in realty

it is not so. It the applications are properly filled in, the

results are guaranteed. Invariably it is the first time that

things appear difficult. Consultants are also available for

liaison and taking care of the paper work on nominal fees.

Conclusion

The

growth of the Internet in India has been slow in comparison to

western countries. This is mainly due to lack of proper

infrastructure particularly in the area of "last mile"

connectivity. Wireless offers a cost-effective solution for

speedy growth. The licensing procedures though appearing

cumbersome are really not so. Quite a few ISPs have already

started using wireless in the "last mile"

connectivity. They are the ones who will be able to provide

better Quality of Service (QOS) and ultimately grow in this

field.

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