Despite the ongoing economic slowdown, wireless technologies, networks and business opportunities continue to evolve at a good pace, according to Andrew Solutions, the CommScope Inc division which provides end-to-end products and systems for wireless communication networks.

As wireless operators worldwide look towards higher speed 3G data networks such as HSPA+ and next generation technologies such as Long Term Evolution (LTE) and WiMAX, they are faced with three critical challenges – namely:-

How to reduce costs while increasing network coverage, how to incorporate environmentally friendly solutions into the network and how to deploy LTE and WiMAX the right way, the first time.

Andrew offered these solution in a single Join The Evolution package at the recent CommunicAsia2009 exhibition in Singapore in June.

“To achieve performance of LTE and WiMAX networks, the location of the antennas, the type of antennas, in building coverage and shared services dynamic technologies are required and problems of fading and path loss are issues especilly with frequencies above 2GHz used by WiMAX, 3G and LTE, and there's always the question of coverage,” said Martin Dawson, Andrew senior manager and chief product architect, Geometrix Location Centre.

Wireless networks are evolving in Asia, some parts of which are already looking at fourth generation (4G) technologies but there's no need for operators to shut down their existing networks but they can provide an overlay of it.

Also, there's a huge diversity in networks and services in demand across the region. For example, voice and basic data such as SMS are being provided for the very first time to many subscribers in India and Vietnam. Between 10 and 15 million new subscribers are being added each month in India and many of them provide their operator with an average revenue per user (ARPU) of US$1 or US$2 per month, and some have not had telecommunications service before.

On the other hand in countries such as Japan and Malaysia, customers want more from cellular services, such as mobile content, applications and so on and they also demand a high quality of service (QoS), so operators must provide in-building coverage as well.

In addition to coverage, indoor environments are also a challenge for location services especially if they rely on GPS equipped devices which have difficulty acquiring GPS signals in indoor environments. Assisted GPS (A-GPS) is a technique that is used to effectively improve the sensitivity of GPS devices.

The A-GPS service is provided by the network which can determine the approximate location of the device based on the serving cell or, more accurately, by using other network timing and signal strength measurements.

Similarly, through a connection to a global network of reference receivers, the network knows the current state of the continuously moving satellites in the GPS constellation. Using this knowledge, the network knows which satellites should currently be above the horizon for the device, which are moving toward and away from it, and what the associated Doppler shifts should be.

This “assistance” data is then sent to the device which uses it to optimize the process of signal acquisition and location calculation. Andrew has also developed technology that couples with indoor distributed antenna system (DAS) deployments that can provide high accuracy location results even for non-GPS equipped devices in indoor environments.

Location-enabled networks facilitate a whole range of value added services such as location-based advertising, child finders, social networking and emergency services.

“Almost all Tier 1 cellular carriers in North America have Andrew location platforms for emergency and value-added location based services” said Dawson.

Besides reliable, high-speed data services such as mobile gaming, streaming video and location-based services, customers also demand clear and consistent voice coverage at lower costs, which presents challenges to operators to keep up or even stay ahead.

One of the solutions is Andrew's 2.3 – 2.7 GHz applications for LTE and WiMAX, as this spectrum helps operators deliver maximum interoperability, high bandwidth, peak performance and is cost-effective to deploy but the technology also presents unique challenges to operators as well.

It minimises channel interference, since as demand grows, the more effectively systems can manage signal interference, the higher the cell capacity it will have, hence higher profitability for operators.

One of the best ways to achieve this is to optimise the shape of the radiation pattern of signals transmitted to reduce interference.

The radiation patterns from an antenna is not an ideal beam pointing in one direction like the beam of a torchlight, but rather it radiates a main lobe pointing in the desired direction, with smaller, less powerful sidelobes to its left and right plus even smaller lobes pointing behind, all of which  which contribute to interference, which would be reduced if these sidelobes can be suppressed.

Other issues include pattern rolloff, back lobe interference based on the ratio of the front to the back lobe signals, horizontal beam tracking and bean squint, and the degree of channel interference can be minimised by signal containment through antenna pattern control.

One of the best ways to achieve this is to use high-performance base station antennas (right) to optimise pattern shaping to reduces interference and a well-designed base station antenna system enables operators to achieve long-term success with their network deployment.

In developed countries, LTE and WiMAX can be a complementary overlay to existing 2G or 3G networks or can be used ate the primary access where the others are unavailable, while in rural areas WiMAX can provide an affordable and efficient broadband network.

While WiMAX deployment may be fast and simple, it's imperative that operators find the most cost-efficient, yet effective ways to realise the best return on their investment.

One of the solutions is the Andrew SmartBean antenna system for cellular networks. They have an internal actuation system which allows for quick, parallel, and coordinated configuration changes. This Agile Antenna System can also quickly redirect and widen their coverage area to temporarily cover for sites which are down. Moreover, these antennas can be used anywhere in the world for WiMAX and LTE, including where the 2,5GHz band has been allocated.

The key features of Andrew antennas are:- Low profile 2.3 – 2,7GHz DualPol cross-polarisation antennas with variable electrical beam tilting and remote electrical tilt; vertical and dual polarised models; 40 dB front-to-back lobe signal ratio; and 0 to 10 degrees variable electrical downtilt, which can be adjusted manually or via a factory installed Teletilt actuator

Andrew antennas also enable the more efficient use of equipment by supporting multi-band, multi-mode operation within one antenna module containing different sets of antenna dipole elements inside for the different frequencies and modes, for example, 3G at 2.1GHz and WiMAX at 2.3GHz or 3G at 2.1GHz and GSM at 1800 MHz and so on.

Going green

Mobile operators are also looking at ways to go green by reducing their environmental impact, which led Andrew to develop its EcoPower hydrogen fuel cell cabinet solution for wireless networks which eliminates the need or lead acid batteries and diesel generators and hence have a lower carbon footprint, since they combine hydrogen and oxygen gases to produce electricity, while their by-product is only heat and pure water.

A rather old technology, fuel cells were first used around 40 years ago to provide power on NASA's two-manned Gemini spacecraft.

Other sources for generating sustainable energy are photovoltaic cells which require a lot of space but have low efficiency, while wind turbines require large structures. The power output from both vary with the intensity of sunlight or the speed of wind at different times of the day, hence they both require energy storage which usually are batteries and both are costly to install.

Fuel cells on the other hand produce a lot of power for their relatively small size, are highly efficient with low operational costs, can produce power continuously since they don't depend on the natural elements hence are best suited for telecom backup power applications.

Fuel cells can also be put in the same enclosure as the base station, instead of having a separate enclosure for the base station equipment, another for the batteries and the diesel generator outside.

They can also be monitored remotely over the Internet and are scalable, with more modules being added progressively as demand increases.

“For example, the fuel cells Andrew provides weighs 100 kg, is about the size of a small fridge and produces eight kilowatts of nett DC power,” said Anil K Trehan, Andrew chief technical officer, Carrier Solutions.

“Gaseous hydrogen is widely available from many producers, so it's easy to obtain and moreover fuel cells have 50% efficiency (ie. in terms of their electrical energy produced for fuel input) versus diesel engines which have only 10% efficiency. While fuel cells are currently used for backup power, they can eventually be the primary power source,” Anil added.

Trivia: If you car's internal combustion engine has the same energy conversion efficiency as a fuel cell it would travel five time father on a litre of fuel than it does now, so 90% of what you're paying for fuel is lost as heat. Jet engines used on planes are said to have an energy efficiency of 20% or twice that of diesel engines. Fuel cell powered cars, well one day perhaps and minus the pollution.

Besides the above, Andrew produces a whole range of wireless communications network equipment, accessories, network planning software and solutions, including for OEM (original equipment manufacturer) customers.

It recently announced the expansion of its production plant in Suzhou, China which produces base station antennas for Chinese operators, for the rest of Asia and elsewhere. Andrew will increase the plant's 20,000 sq m production floor space by 50%  and add 400 persons to its current 2,000 staff.

Some of Andrew's recent wins include:-

• Wireless Infrastructure project for Sinopec Zhenhai Refining & Chemical Company in Ningbo, China
• Provider of wireless coverage infrastructure for China’s high speed Shijiazhuang-to-Taiyuan railway (Shi-Tai line).
• Installation of new HELIAX FXL aluminum cables in China’s Environmental Ministry Building.
• Tetra project upgrade with MTRC in Hong Kong.
• Provision of wireless coverage infrastructure for Beijing Metro ahead of the Olympics.
• Provision of wireless coverage infrastructure for the new head office at Macquarie Park Campus in Australia.
• Supply of new HELIAX® Aluminum Cables to Nokia Siemens Networks India for their aluminum radio frequency (RF) transmission line cable solution in India.
• Provider of wireless coverage infrastructure for a new high speed train between Beijing and Tianjin, China.
• 3G network infrastructure upgrade for Singapore’s North-East train line.
• First major WIMAX BSA deal with one of India’s leading telecommunications group.
• First time to develop and supply LTE base stations to a Japanese OEM i.e. Kyocera.

• Only foreign vendor chosen by China Telecom for CDMA network

Recent Awards

• Golden Award for Green Communication Energy-Efficiency Technology by China Information Industry Net (affiliate of the China Ministry of Industry and Information Technology).
• Global Core Partner Award by Huawei Technologies for outstanding support and delivery performance.

• Best Service Teamwork Award by China Association of Communication Enterprises for outstanding contribution toward natural disaster relief and Olympic Games communications networking support.