CONNECTIVITY: An Option in Sight

Given the geographical diversity of India, last-mile connectivity has always

been a pain point for telecom operators. In the case of business centers, laying

down fiber and wiring up old buildings is a herculean task. All this, coupled

with the approvals required for digging and laying down fiber or copper, makes

it difficult to provide high-bandwidth, reliable connectivity. And, after the

broadband policy failed to unbundle the copper loops of BSNL/MTNL, private

operators have been aggressively pursuing the fiber and wireless routes to

deliver high-speed connectivity.

Free space optics (FSO) promises to solve the last-mile woes and is also

being promoted as a reliable backhaul technology for the carriers.

FSO

as a technology was initially used in defense (primarily in naval ship-to-ship

communications) and secure aerospace applications. It is now also an alternative

to fiber optic—based solutions in the commercial market space.

According to industry estimates, the worldwide FSO market at present is about

$100 mn. The potential, however, is of more than $1 bn. "FSO has been

popular in USA with almost 50% of the market. It is followed by EMEA with 30%

share and Asia-Pacific contributes 20%," says Jeff Bean, director global

marketing, LightPointe. According to statistics, there are 750,000 large

business buildings in the US, of which only five% are connected to fiber, but

over 70% of which are within one mile of at least one of the buildings that is

connected to fiber.

In India, though pilots and testings have been carried out, deployments have

been few. On the enterprise side, Krone has deployed this technology from

Optical Access, an Israel-based company, at its Chennai-based Orchid Chemicals

and Pharmaceuticals. Bharti is said to have tested and deployed this for its

backhaul. The technology for this was provided from SONAbeam, through Netware

Technologies India. "The installations are primarily for mobile wireless

backhaul. However, enterprise building-to-building opportunities are starting to

emerge," adds Bean.

The Tech Side



Free Space Optics, also called free space photonics (FSP) or optical

wireless, refers to the transmission of modulated visible or infrared (IR) beams

through the atmosphere, to obtain optical communications. Like fiber, FSO uses

lasers to transmit data, but instead of enclosing the data stream in an optical

fiber, the data is transmitted through the air.

FSO transmits invisible, eye-safe light beams from one 'telescope' to

another, using low-power infrared lasers in the terahertz spectrum. The beams of

light in FSO systems are transmitted by laser beacons towards highly sensitive

photon-detector receivers. These receivers are telescopic lenses capable of

collecting the photon stream and transmitting digital data containing a mix of

Internet messages, video images, radio signals, or computer files. Commercially

available systems offer capacities in the range of 100 Mbps to 2.5 Gbps, and

demonstration systems report data rates as high as 160 Gbps.

Will It Replace Fiber Optics?



FSO, as a technology, has all the potential to compete with the optic-fiber
cable. FSO is easy and fast to deploy, cost of deployment is less, apart from

that, no spectrum clearances, charges, or permission is is a hinderance. An

estimate by LightPointe says (according to a media reports), in India, the 10 km

range connectivity in STM 1 mode, which provides 155 Mbps of bandwidth over

fiber optic connectivity, will cost around Rs 75 lakh; while FSO connectivity

for that will cost around Rs 25 lakh.

Despite the benefits, FSO is not seen to be on its way to completely wipe out

the optical fiber. Rather, both the solutions are seen as complementary to each

other. FSO works well for connecting buildings within a limited area, typically

within a 4 km radius.

Similarly, for the carriers this works well where line of sight is available

but other options like digging for cables are not viable. In fact, VSATs give it

strong competition, when it comes to wide-area connectivity.

Lest One Forgets



The biggest drawback for FSO is that the performance goes down in extreme

weather conditions. Being a line-of-sight technology, interference of any kind

(like water, snow, radiation) can pose problems. Under foggy conditions, its

efficiency levels become doubtful. FSO systems can transfer high-speed data and

have common link for distances within 1—2 km, but inclement weather can reduce

this to 500—1000 meters. The laser beam that carries data for an FSO link is

adversely scattered by the water droplets in fog, and cannot reach a remote

terminal more than about 200 meters away. India has a tropical climate, with

weather conditions varying from extreme heat to heavy rains and thick fog. All

this casts a shadow on FSO adoption rate here.

Also, it is a very high-cost technology and systems for one deployment cost

around $7000, as a one-time capital investment. Companies promoting this

technology say, a comparison with low-bandwidth wireless options makes it appear

costly but the actual cost-per-bit analysis shows it to be less expensive.

"It's a matter of supply and demand. If you demand high bandwidth, but

can't find a supply, you're sunk. We supply high-bandwidth (on a par with

optical fiber cable) that no other low-bandwidth or licensed wireless can

remotely match it," says Bean. To overcome the cost factor, companies are

working to launch low-cost entry-level systems by 2006.

Free Space Optic Security



Wireless, by its nature, is perceived to be insecure. FSO emits infrared (IR)

beams for communications. To intrude these, beams have to be tapped. But, being

a duplex technology, it would require tapping devices to be on both ends,

increasing the chances of the intrusion being detected. Determining the size of

the beams and putting nonreflective surfaces around the equipment reduces

chances of these being tapped. Also, the time-tested method of encrypting the

data traveling over FSO ensures greater security.

Another concern in the case of beam-based technologies is that the beams may

miss the target equipment or spill beyond them.

FSO has all the properties needed to fulfill the rising demand for higher

bandwidth solutions to meet the needs of corporations and individuals. If minor

irritants are removed, it can augment the legacy WAN technologies in providing

secure, redundant links between corporate resources, the Internet, and the

telcos.

Anurag Prasad

FSO Equipment Providers

LightPointe



#402, 6-3-676/1 Durganagar Colony, Panjagutta,



Hyderabad —500 082; Phone: 91-405-5165133


Website: www.lightpointe.com

Terabeam



8000 Lee Highway, Falls Church, VA, 22042;



Phone: +1 888-297-9090


Website: www.terabeam.com

Optical Access



MRV Communications, Inc. Corporate Center


20415 Nordhoff Street, Chatsworth, CA 91311


Phone: 818-773-0900


Website: www.opticalaccess.com

AirFiber



16510 Via Esprillo, San Diego, CA 92127



Phone: 858/676-7000


Website: www.airfiber.com

Cablefree Solutions



Cablefree House, 1 St. Clare Business Park, Holly Road


Hampton Hill, Middlesex TW12 1PZ UK


Phone: +44 (0)20 8941 7975


Website: www.cablefree.co.uk

fSONA Systems



1750 Tysons Blvd., Suite 240, McLean, VA 22102 USA



Phone: 1-877-463-7662


Website: www.fsona.com

PAV Data Systems



Suite B-08-06, Block B, Plaza Mont ' Kiara



No 2 Jalan 1/70C, Mont ' Kiara, 50480, Kuala Lumpur


Phone: +603 6203 2010; Website: www.pavdata.com

Plaintree Systems



110 Decosta Street, Arnprior, Ontario, K7S 3X1



Phone: +1 613 623 3434


Website: www.plaintree.com