With an increase in the number of private operators in basic, cellular, and DLD, there has been an increase in the demand for optical fiber cable (OFC) in the country. Service providers as well as utility public sector companies have been deploying OFC in large quantities. In future, polyethylene insulated jelly-filled (PIJF) cable requirement is going to come down with the increase in usage of fiber and other wireless technologies.
Polyethylene insulated jelly-filled cable (PIJF): PIJF is an assembly of a number of pairs of copper wires. The gap between the pairs of wires is filled with petroleum jelly to reduce noise and transmission losses. Each line has two wires—one for incoming and the other for outgoing.
Prior to 1980, DoT was using paper covered unit twined (PCUT) dry core cables. The primary cable had to be protected from moisture. With the introduction of PIJF cable, DoT took a decision to discontinue the use of PCUT cable. There are two types of PIJF cables in use—solid PIJF cable and foamed PIJF cable. In case of the solid PIJF cable, the conductor is insulated with solid polyethylene. This type of cable is presently used in the DoT network. In case of foamed PIJF cable, the conductor insulation is foamed to form a cellular cross-section, with a suitable foaming agent.
Optical Fiber Cables (OFC): OFC offers almost unlimited bandwidth and unique advantages over all previously developed transmission media. OFCs are no longer dominant only in the transport network or feeder line but have penetrated to a large extent in the subscriber loop as well. With fiber, one can transmit narrowband, wideband and broadband communication services to the end-subscriber through POTS, ISDN phone, video phone, and video-conferencing. To supply all these services with data rates up to 2.5 Gbps, single mode fiber pair is necessary.
|Comparison Between Coaxial, PIJF, and OFC|
|Application||Last mile mainly for cable TV network||Last mile mainly for the access||Backbone, access metro for converging solution|
|Attenuation||More than 3 dB||More than 3 dB||Less than 0.38 dB|
|Bandwidth||Very very less. One can go up to 2 Mbps||Very very less. One can go up to 2 Mbps through DSL and ADSL||Large amount of bandwidth and can go from Gbps in the access to Tbps in the backhaul|
|Cost||Cost in terms of bandwidth is more; cost in terms of pair is less||Cost in terms of bandwidth is more; cost in terms of pair is less||Cost in terms of bandwidth is less Backbone OFC cost is 1.5 times of PIJF cable|
|Interference||EMI interference Needs shielding from lightning and electrical short circuits||EMI interference Needs shielding from lightning and electrical short circuits||No interference No shielding required|
Following are the advantages of OFC over other transmission systems:
The ability to carry much more information and deliver it with greater fidelity than the copper or coaxial cable
OFC can support much higher data rates and at greater distances than coaxial cable
OFC is immune to all kinds of interferences, including lightning and will not conduct electricity even if it comes in direct contact with high-voltage electrical equipment and power lines
As an optical fiber is made of glass, it will not corrode and is unaffected by most chemicals
An OFC, even the one containing many fibers, is much thinner and lighter in comparison to coaxial cable with a similar information carrying capacity. It is easier to handle and install, and uses less duct space
OFC is ideal for secure communication systems because it is very difficult to tap but very easy to monitor.
Pricing: The key buying parameter in government (BSNL, MTNL, and Indian Railways) tenders is the price as long as the optical fiber cables meet the required specifications. On the other hand, the private operator, which contributes a small portion of the overall OFC sales in the country, pays more stress on the quality of fiber.
While buying optical fiber cables, carriers and enterprise customers should focus more on optical parameters, as most of the problems are due to impurity of glass.
Dispersion Slope: Different fiber manufacturers have different dispersion slopes, which is proprietary. Different OFC manufacturers in the country use different standards, which is just a marketing gimmick used by manufacturers. Lower the dispersion slope, the better it is.
End-to-End Attenuation: The reduction in signal strength is measured as attenuation and the unit is decibels (dB). The light passing through fiber will not disperse if the fiber cladding is uniform throughout the length of the fiber. So attenuation loss can be minimized if there is uniformity. The permissible limit for 1,310 nm is 0.38 dB/km while for 1,550 nm it is 0.22 dB/km.
If the attenuation level decreases, it is good, but if it increases then one has to increase the number of repeaters, which will result in an increase in transmission cost. In majority of fibers, the attenuation loss varies from 0.19 dB/km to 0.33 dB/km and there is an increase of 0.01 dB/km once the fiber is transformed into OFC.
Attenuation Under Stressful Condition: Under this condition, OFC is put under stress and the cable is tied on either side, and 2.7 Newton weight is applied on both the sides. The maximum attenuation variation should be 0.4 to 0.5 percent. Once OFC is relaxed, it comes back to the normal position. Under pressure, the cable should not break. This is used mainly for duct and buried type of OFC.
The buyer should also look at other mechanical and optical properties like mode field concentricity (shows how uniform an OFC is), cut-off wavelength, splice loss, and fiber loss per km (dependent on the transmission equipment).
Polarized Mode Dispersion: This tests the optical characteristics of OFC in polarized mode whereby one can test how much light goes out and how much light remains inside the fiber.
Chromatic Dispersion: It depicts the number of wavelength that is attenuated and the strength of the signal.
The large-scale deployment of cables by carriers has given a big boost to the telecom cable industry in India. Suddenly, all types of carriers, from basic service providers, cellular service providers, domestic long-distance service providers, and ISPs, to utility service providers like GAIL, PCIL, and Indian Railways, have been deploying telecom cables in large numbers, in a number of locations.
The Indian telecom cable market is estimated at Rs 4,317.51 crore (excluding the cables that have been imported) for 2000-01. In 1999-2000, the telecom cable industry was valued at Rs 3,685.31 crore (revised from the earlier figure of Rs 4,000 crore published in the July 2000 issue of VOICE&DATA). The excellent performance of the industry can be attributed to an increase in plant utilization, remunerative prices fixed by BSNL, and buoyancy in prices of raw materials like copper and fiber.
|Worldwide Deployment of Cable Fiber by Application (000s of F-km)|
|India Long Distance||1,200||2,000||6,000|
|According to KMI, USA the global market of optical fiber cable is growing at a rate of 15.2 percent per annum and the demand growth from the developing countries will be 2.5 to 3 times the demand growth from the developed world. It is estimated that by 2006, the worldwide installation of OFC will be 290 million fiber km by 2006|
The industry has achieved a growth of 17.15 percent in 2000-01. On the OFC front, cable manufacturers have imported cables from the worldwide market, as there was a shortage in the Indian market. However, the jelly-filled telecom cable (JFTC) market was entirely taken care of by the Indian manufacturers.
On one hand, Hindustan Cables was the No 1 player on the JFTC front, followed by Sterlite and Finolex. On the other hand, Sterlite Optical was the No 1 player on the OFC front, followed by Aksh and Hindustan Cables.
The total OFC market, in terms of rkm, for the fiscal 2000-01, was 2,55,000, which catered to the Indian market as well as to the export market, whereas the total JFTC market in India was estimated to be 638 lakh cable kilometer (lckm)
Public sector units like BSNL and MTNL are still the bulk buyers of JFTC and OFC cables in the country. But of late, private players have begun to source cables in a big way.
Seeing a huge opportunity in the telecom cable market, many new entrants like Enigma, National Cables, Reliance Engineers, Uniflex, and West Coast have started cable manufacturing setups in different regions of the country.
Despite the huge demand in the fiber cable market, the industry is facing a shortage in terms of raw materials. So on the OFC front, companies have started doing backward integration by setting up preform and fiber drawing factories.
The demand for fiber outstripped the supply, and the shortage of fiber worldwide and in the Indian market led to an increase in the cost of optical fiber cable and fiber in the market. The cost of drawn fiber reached a peak of Rs 5,500 per km and is presently hovering around Rs 4,700 per km.
Cable Companies in India
|Rank||Company||JFTC (in lckm)||OFC (in rkm)||Revenue (in Rs crore)|
|12||Tamil Nadu Telecom||9.46||7,769||113|
This year, BSNL is planning to go for distributed switching technology that will help optimization on the JFTC cable network. The plan outlay for BSNL in 2001-02 is to deploy 473 lckm of JFTC and if possible, to cut down on lckm. This translates into a drop of around 19 percent.
Since it is warding-off competition from Reliance, BSNL is very aggressive on the infrastructure side. The company has already given an order worth 441 lckm of JFTC cable, this fiscal. MTNL has also come up with a tender for 17 lckm this fiscal. On the OFC front, the company has floated a tender for 1,00,000 rkm.
This year, there will be an increased requirement of telecom cable from Reliance Infocom, Hughes Tele.com, Bharti, Tata Teleservices, Shyam Telelink, and HFCL Infotel. This year, the private basic service providers will deploy around 100 lckm of PIJF cables and around 30,000 rkm of OFC in the country, whereas BSNL is planning to deploy 126,000 rkm, an increase of 26 percent from the previous year’s planning. But in terms of actual deployment, the growth translates to a whopping 133 percent.