Telcos Move to Digital Power

Indian telecommunications industry is a highly dynamic sector which is fast growing. There is a need for highly reliable power solutions to meet the requirements of multiple infrastructure applications. The vast telecom sector has equally huge infrastructure which is a major power consumer affecting the environment as well as power conservation. Power consumption represents one of the top 5 economic opex considerations. It is a concern for carriers due to fast rising electricity and diesel costs. Power is vital to telecommunications and other business operation. An effective energy efficiency programme helps reduce costs and environmental footprint as well. Telcos are eyeing a well equipped and a firm base for power management systems.

However, the consumption of energy (electricity and fossil fuels) comes with some environmental and social responsibilities.

Telecom Power Consumption

More than 70% of energy is being consumed by towers. Each tower requires energy from 1,000 W to 3,000 W (older installation consumes more power as compared to new ones because of technological advancement). Each 1,000 W results in 0.22 tonnes/hr of emission of carbon dioxide if running on state electricity; in case of private gensets this number is many times more, assuming average power consumption of each tower is 1,200 W. The tower sites consume 65% energy, while the core network accounts for 21%. Each tower requires $50,000-60,000 for electronic hardware and half of this is required for installation and other things. Apart from this additional capital is required for the genset, battery backup (gensets are required in urban areas also for emergency backup) which requires close to $5,000, so total cost of ownership of a telecom tower is close to $100,000 (for 2G). These towers have an opex of $8-10k per year which is mostly the cost of energy (rural has higher energy bill because of diesel and urban areas have higher rental costs). But it is really surprising that not even 5% of these towers are running on solar power. Probably operators are already struggling with capital availability so they opted for more costly approach.

Indian telecom industry is consuming around 2 bn l of diesel every year for maintaining its mobile towers. The consumption will go up further when the new operators launch their services and the existing operators expand their network further to launch 3G and BWA services. There are around 3,30,000 towers across India. At present telecom network consumes more than 70 per cent of energy and 200 crore liters of diesel every year. Towers in India is expected to expected to increase to 450,000 towers in the next 3 years.

Industry players have realized the need of power management. The market for energy efficient power management and monitoring solutions for telecom is slated to expand considerably in the next 2 years. They are opting for more reliable technical developments to increase the efficiency of base stations, reducing the effect on the environment and reducing costs. The telecom systems are designed with redundant power. AC power is the main source backed by lead acid batteries and then by generators. Multi-service operators (MSOs), data centers, disaster recovery sites and base stations have this redundancy built into the power architecture. The power system at an unmanned site, therefore must be extremely reliable, rugged enough to withstand changing weather conditions, and with as little human intervention as possible. In case something goes wrong, it must be able to communicate an alarm signal to the nearest manned station and be able to sustain the solar power system's operation for a period long enough for maintenance personnel to arrive.

Outdoor Base Transceiver Station (BTS) has become more popular and telcos are taking extra measures to bring down power costs. Outdoor BTS significantly reduces energy spend, as it requires little or no cooling, does not require a shelter, and is easy to maintain.

The air interface between the mobile station (MS) and the BTS uses LAPDm protocol for signaling, to conduct call control, measurement reporting, handover, power control, authentication, authorization and location update.

Trends

The current trend in the power management industry in the context of telecom applications is energy efficient products and solutions to help operators reduce their operating expenses significantly, address the economic feasibility issue on one hand and environmental concerns on the other hand. Telcos have been deploying energy efficient power solutions for BTS. Deployment of solar sites is gaining popularity and renewable sites seem to be the way forward. Telcos are exploring battery technologies that can withstand higher temperatures, more charge discharge cycles that are long-lasting and involve low capital expenditure.

They are adopting efficient products and solutions that reduce power consumption, cooling requirements and occupy a smaller footprint.

They are moving to digital power from conventional analog power supplies which are flexible and have better monitoring of power rails. Digital control has been one of the most important developments in power supplies over the last few years. When combined with best analog design practice, digital power is an enabling technology through which board-level power modules can be integrated into other digital circuit elements such as processors and memories. This gives system architects the ability to precisely monitor and control the level of energy delivered under changing conditions.

Earlier BTS site comprised of various equipments such as rectifier, genset, battery, etc. These equipments would have serious compatibility issues that makes the site less reliable. In recent times, new integrated site solutions have been introduced in the market that make the BTS sites more reliable and efficient even if one of the equipment would be down, rest of the site would still work perfectly ignoring the fault.

Renewable energy is always more beneficial than conventional energy. Even now the government has also recommended that all towers should be running on the renewable/green energy with a 40% load factor. There are site solutions available with solar technology to cut down on fuel charge and carbon emission. Telcos are focusing on the business opportunities and challenges associated with improving the energy efficiency of fixed and mobile telecom networks, reducing associated carbon emissions, and utilizing renewable power sources such as solar energy, wind energy, and fuel cells. There are site solutions integrated with solar panels, wind energy, and bio-fuel.

A few telecommunications carriers now target a 20% power reduction per year on the equipment they deploy. This is a response to increasing power consumption in central offices, which is due to higher bandwidth capacities, increasing linecard port densities, more intelligent processing requirements and more complex chip implementations. Higher power consumption equals higher operating costs for telecom providers, and leads to more complex engineering challenges for equipment suppliers dealing with thermal management.

One of the major challenges is the lack of appropriate regulatory measures for rolling out projects. A telecom player witnesses the highest per unit cost of downtime amongst all major business sectors in the country. However the present state of disruption in the sector has lead to a capex crunch. Many of the rural BTS sites are still running on old technologies and less efficient equipments. Upgrading these old sites involve a huge investment. Deploying reliable, environmental friendly and robust solutions in remote areas and receiving data is another challenge. Early detection of failures is a major concern due to the remote access.

Power consumption has always been a major consideration when building systems. The issue is not only of global warming or adopting the latest trend. Carrier operating costs have grown as more sophisticated cooling systems are needed and more electricity is consumed, thereby leading to higher energy costs. This is only compounded by the fact that energy costs have risen considerably of late. Meeting strict power efficiency requirements is a major challenge for system developers. Reducing power consumption by 20% is not trivial as power consumption has increased over the last few years.

Green Deployments

Telcos have deployed renewable energy solutions—solar, wind power, and bio-fuels targeting rural markets for efficient power supply. The initial investment for a solar solution is around `40-45 lakh. Industry needs network management solutions which can take care of utility power monitoring, power system/battery DG/air-conditioners/site access monitoring and control. These solutions should be modular and compatible with old legacy sites and also reduce carbon emission. Factors driving power management in telecommunications are size, thermal management, cost, and electrical performance (regulation, transient response, and noise generation). Circuit boards and systems are also being designed to achieve green goals.

The use of renewable sources of energy such as solar and biomass, better network planning and sharing of infrastructure by different operators could substantially reduce the carbon footprint of the industry-Trai has suggested in a consultation paper recently. The move from diesel to solar and other alternate sources of energy will result in a reduction of 5 mn tonnes of carbon emission as well as a savings of $1.4 bn (`6,350 crore) in operating expenses for telecom tower companies.

The key to green telecom is to manage both demand and supply of power at cell sites. Therefore renewable power sources are an excellent choice for many emerging markets, because they contribute to the low total cost of ownership that is vital for providing affordable communication services to the subscribers. Last year the government made positive moves in this direction by increasing expenditure by 61% towards realizing its target of generating 20,000 MW of solar power by 2022, and offering subsidies on equipments for harnessing wind, solar, and geothermal energy sources (announced in union budget 2010-11). We also welcome Trai's contemplation in coming up with a consultation paper on green telecom. Such initiatives will encourage companies to develop environmental friendly products and solutions to promote the green cause. High efficiency rectifiers, advanced controller, site monitoring and control unit, cooling solution, solar hybrid solution and network management solution can contribute to all this.

Efficient Power Consumption Solutions

According to a report average power consumption during power outrage per tower is 5-6 KW for 8 hours of diesel generator, which means an average consumption of 4,000 l of diesel every year, implying the telecom consumption of 1.8 bn l of diesel every year.

In today's power hungry times, efficient power management technology is of critical importance. Energy efficient power solutions are no more an option for telecom operators these days. It has become a necessity in a market where margins are nosediving due to tariff wars, denting the profitability of the mightiest. The telecommunications environment characterized by increasing customer demand for new products and services, emergence of new competitors and a rapidly evolving technological landscape requires a fast and responsive business model. Integrated site solutions are always more reliable and more energy efficient.

There are some intelligent software applications available that can help monitor the power consumption at the BTS sites. Even government has also launched the USO fund for the telcos to help them upgrade their old sites in rural areas. Furthermore in mature markets, energy accounts for up to 10% of an operator's opex while in emerging markets it can be as much as 30%.

In order to achieve energy efficiency and reduce expenditure, companies have to resort to end-to-end solutions that are adaptive and scalable and can be adjusted to changing operational requirements. DC power plants with high efficiency rectifiers, integrated power management systems, industrial inverters and outdoor enclosures are the essential parts of a customized solution that can be employed to improve over-all network efficiency. PoE is very helpful for powering IP telephones, wireless Lan access points, cameras with pan tilt and zoom (PTZ), remote ethernet switches, embedded computers, thin clients and LCDs. All these require more power than USB offers and very often must be powered over longer runs of cable than USB permits. In addition, PoE uses only one type of connector, an 8P8C modular connector whereas there are numerous types of USB connector.

Smart grid is an innovative solution that can help reduce power consumption. It is a smart metering system which effectively manages power consumption and maximizes it for better use. The system identifies which all power appliances draw the maximum power, which time of the day they are active at, and how you can effectively use them to avoid wastage.

Digital power sources manage energy delivered to the load, monitor and control operational parameters, and make it easy to remotely reconfigure the system without sending an engineer to the remote site. It is assumed to be the most promising advancement for the future success of system power management.

Malini Nagaraj
malinin@cybermedia.co.in