AIRPORTS AND LAND SYSTEMS: LEARNING FROM SUBMARINE CABLES & ELECTRICITY MARKETS

Transcription

1 conference & convention AIRPORTS AND LAND SYSTEMS: LEARNING FROM SUBMARINE CABLES & ELECTRICITY MARKETS Jorge O. Garcia Lozano (Telemediciones S.A.) Telemediciones S.A., Carrera 46 No Bogotá, Colombia South America Abstract: Power Feed equipment is a sophisticate component in a submarine Cable System. The combination of both Constant current and DC Voltage could be the missing link for a great number of applications where AC regulation is affected by span length. Airports would be one the best scenarios for this technology, if perimeter surveillance systems would use DC Power instead AC Power to feed cameras, sensors and any combination of access or proximity control. A power principle taken from the depths is then the key factor to this proposal. Unarmored cables, COTDRs, High Loss Loop Backs with optical amplifiers devices and Network Management Systems, complete the terrestrial application using sub sea technologies. With both submarine and terrestrial networks, working under same references and being operated at the same time as a global network, it is possible to envision the management of the World Telecommunications Capacity as a big grid that could be operated as actually the New Electricity Trade does. 1.0 A NEW APPROACH TO USING PFEs IN AIRPORTS. Common components between an airport telecommunications network and a submarine cable System are almost nil at present, but could be significant in the future if a Submarine Power feed Equipment (PFE), could be adapted to the peripheral wiring of an airport to feed the surveillance infrared systems including television cameras, proximity sensors and systems for lighting control in taxiways and airstrips. The powering for such services is actually being implemented from the AC power grid, with encapsulated transformers spaced about 500 meters, and AC/DC converters located near to the beacons or inset lights. PAPI (Precision Approach Path Indicator) are also considered because they are powering under same scheme. This solution requires additional stranded copper cable or fiber optic cable for remote control of the monitored services buried in pipes parallel to power lines. Copyright 2010 SubOptic Figure 1, shows the approximated location of a hypothetical set of 340 monitoring points in El Dorado airport in Bogotá Colombia, spaced around 50 meters along a perimeter of 17 kilometers. The traditional solution for this case requires a mesh of medium voltage cables, besides many control cable boxes, one on each manhole, especially where lights or cameras are placed. Would be desirable however, if the same type of services and needs could be provided through a single cable, just one power supply system, a single management system and a single maintenance liaison operator. DC Power Systems, have advantages from regulation view point, require less cabling, are a probed technology and could be the origin of global applications if successful test Figure 1 Page 1 of 5

2 Red line is the integration of 50 meters spaced manholes, giving the appearance of a continuous line. Figure 2 shows schematically how an undersea cable technology, it can solve the riddle above, simplifying the operation, maintenance and management, of perimeter surveillance systems at airports around the world. The order of magnitude of a PFE for Airports, and depending on the type of cable used to equalize the application, should be about volts DC, with a current between 1.0 and 1.6 A, a resistance cable of about 1.0 Ohm per kilometer, 24 or 48 Volts Zener Regulators and the capacity to drive loads more than 50 Watts. This value may be sufficient to activate and move cameras and also to feed the media converters to carry the video information to the Video Management center. OP x +1 OP 339 OP x Opx- Video cameras, Proximity, Infrared & Pressure Sensors OP2 Table 1 is a comparison between both Submarine and Airport PFE characteristics. The great difference lies in the span length. While the separation between submarine repeaters can be around 120 km, in the airport systems the separation between control boxes, cameras or lighting systems should not exceed 50 meters, however the PFE balance is compensated due to the high number of regulators required to feed the control boxes. OP bat bat LV + HV PF PF Figure 2 Every 50 meters, a power module to feed cameras and control boxes is inserted in series with the cable. The control boxes which would store and would supply power to the monitoring and television camera systems are similar in principle to a submarine repeater. Inside these boxes are the DC Regulators and all the electronics associated with the solution. OP1 Extreme Application Characteristics Submarine Cable Airport Cable Current (A) Voltage Drop Repeater / Control Box (Volts) Resistance (Ohm/Km) Fibers 4 96 Total Length (Km) Span Length (Km) Number of Repeaters / Control Boxes Magnetic Storms (0.2 V / Km) Typical PFE (KVolts) Table 1 Copyright 2010 SubOptic Page 2 of 5

3 The carefully observation of the Airfield Lighting Manufacturers and Suppliers, shows they have produced for many years AC and AC / DC solutions based on the AC transformation, instead to feed cables directly with direct current power as submarine cables does from century XIX. One further step to change this paradigm should be to consider the following ideas. 2.0 MORE INFORMATION ABOUT POTENTIAL APPLICATIONS. At a glance, a centralized monitoring System, like used in the New Submarine Cable Networks, could verify the operational status of all perimeter cameras. Through a dedicated OTDR with an appropriate dynamic range, connected in daisy chain and using at least one fiber per each buffer, it will be check the integrity and optical condition of the fibers used to control the System. Cables could be either lightweight (LW), light protected (LWP) or Single Armored (SA), depending on project requirements with a central core no more than 14 mm diameter. The current to feed the cable, will travel trough the copper center conductor. Are excluded cables for underwater applications like festoon or unrepeated systems, because the copper component of these cables, serves only as a hydrogen blocker. Unlike the long-range submarine cables that use four or six wires, the number required for this application, could be much higher, such as 48, 96 or even more fiber threads. The limit to the number of fibers would depend on the decision to use media converters, dense wavelength division multiplexers or GPON devices. Although the proposal seems absurd, and in order to maximize the remaining elements in the repair works of a submarine cable, and given the high rate of supervision points (Video Cameras), we propose a test bed, consisting of recovered cables from marine repair jobs. Under these conditions and due to reduced operation tensile strength and short spans, a simpler design for the junction boxes would be required. The location of the network elements on the perimeter of airports, demands sub meter accuracy and eventually will be useful to correlate fault events that are manually or automatically detected by the optical monitoring system with a geographic information system. This information may be supplemented with a surface map of the area affected by the lying, using GPR devices (Ground Penetration Radar) or magnetometers, similar to those used in the sub-bottom exploration in shallow waters. The use of proven technology in extremely hostile environments such as the bottoms of the seas is the primary justification to pretend apply them in Airports and terrestrial systems where also high availability is required. 3.0 MONITORING LAND SYTEMS. Since 1997, there is a technology capable of monitoring transcontinental submarine cable systems of over km using COTDRS (Coherent Optical Time Domain Reflectometer). With this potential development, the obvious question then is: What should be changed, added or included in a terrestrial optical communication system to exploit these developments economically without neither impacting operation cost nor reducing the network availability, when events caused by natural disasters or manmade be real fact? To cite a few examples, in the Pan American and Maya submarine cable systems, COTDRs exist in almost all terminals, these devices are capable of monitoring more than 4000 km of fiber in the Caribbean, 4000 km in the Pacific and another 3000 km in the Atlantic between Panama and St. Croix, Copyright 2010 SubOptic Page 3 of 5

4 but they are blind to the back haul, first, by the lack of devices in terrestrial repeaters to replicate the submarine exercise and second, by the policies of the consortium not to share technological resources with other authorities outside the scope of the original design. The probability of using a COTDR is approximately once in 10 years. Any spare time of these expensive super equipments could be used if the existing network elements in submarine repeaters, were incorporated into the terrestrial networks, to provide amplification and optical reflections or returns through the middle HLLB (High loss Loop Back) for real-time and dark fibers, facilitating the monitoring of back haul. The mix of expectant COTDR devices, HLLBs and a detailed data base of laying attributes as spare cable at both sides of splices, could provide very high locate precision without the requirement of the traditional elevation model, worldwide accepted. SUBMARINE AND TERRESTRIAL SYSTEMS CONTROLLED BY JUST ONE COTDR HLLB AO AO MODULE TO BE INSERTED IN EVERY TERRESTRIAL REPEATER Terrestrial System 1 Lenght XXXX.X Km SUBMARINE CABLE SYSTEM 1 SUBMARINE CABLE SYSTEM n Figure 3 OPTICAL SWITCH HLLB y AO Terrestrial System n Lenght YYYY.Y Km COTDR 4.0 NEW TELECOMMUNICATIONS TRADE. With the complex scenario of monitoring submarine and terrestrial segments simultaneously solved, and with the interest of Telcos to share common services previous approval of the national L3 L1 L2 Ln regulator, the next step would be to take from the electricity sector, the lessons learned during the past 20 years related with the stock market and applied without many modifications to the Telecommunications industry, creating at the heads of submarine cables, a series of optical switching nodes, to in case of fault automatically lead to different destinations, the Data, TV and IP traffic converging there with minimum risk of traffic loss. The network should allow accept incoming or outgoing traffic, using distribution channels trough submarine cables or backhaul networks all connected between them [2]. This initiative aims to bring together all the Telecom operators, in a scheme of cooperation to reduce the services restoration time in case of contingency, allowing higher elongations in underwater repairs while avoiding speculation and minimizing risk of collapse or redeemed emerging economies, which rely mainly on Internet services, trough the submarine cables. What would happen if the Fiber Optic Submarine Capacity around the world was based on a Great Grid where holders had the opportunity to sell, resell, buy, rent, restore or distribute capacity according to the demands of the market place in a few seconds? Different types of market forces like Submarine cable Owners (Consortium, Privates and Government), ISP, Telcos, Customers, Regulators as ITU, Cable and System Manufacturers, and many more, are invited to be part of the initiative. The first step could be, create a Blog or a forum, where general guidelines could be sketched and try to find common variables between both markets, to evaluate the feasibility to create the new Global Telecommunications Trade. Copyright 2010 SubOptic Page 4 of 5

5 A detailed inventory of the cable systems indicating owners, technology, length, design, notional and reserve capacity, restoration and backhaul facilities, and hundreds of characteristics are required to prepare the starting basic commercial model. Different studies groups must investigate the successful cases in the Electricity Trading and to propose papers to share between forum participants. The Electricity Trade arrangements have changed the way to generate and distribute electricity to the customers. Similar arrangements are proposed in order to spread services using redundant cable infrastructure, and reduce maintenance, operations and user final costs. The idea will stimulate new developments and applications and will be also a good opportunity to introduce in the Third World, a new generation optical network. Carriers, Internet Service Providers, distributors, content and media developers, and all telecommunications actors, with the guidelines of the local telecommunications regulator or authorities, could change the way to use the info communications highway. 6.0 REFERENCES [1] Google Earth, Caption of El Dorado International Airport in Bogota Colombia. [2] L Vargas, R Palma, O Moya, "Mercados Eléctricos y Bolsa de Energía: Aspectos Críticos para su Implementación en Chile", Base de datos Mercados Eléctricos Competitivos Rodrigo Palma Behnke, Ubicación RP 585, pages 1 a 8. [3] K Neuhoff, "International Electricity Trade Economic Considerations", University of Cambridge, pages CONCLUSION As primary power source to control lighting and perimeter surveillance at airports, the principle of tele powering used in submarine cables is proposed. At the same time and knowing the unmet need for monitoring the terrestrial networks, we suggest the adaptation into terrestrial optical fiber networks, under the COTDRs domains and in the "hibernation" state, of the High Loss Loop Back (HLLB) modules used in long distance subsea systems. To use the idle capacity in both terrestrial and submarine cables is the argument to propose the replica of the Electricity trade in the Telecommunications marketplace. Copyright 2010 SubOptic Page 5 of 5