Wireless Trends – Challenges in a Wireless Multi-Technol ogy Environment

 

There are a lot of different challenges in multi-technology environments; the following issues are among top three:

• Interoperability
• Power efficiency
• Interference

Today, we are at the beginning of one of the first real convergence waves within consumer electronics; the broadcasting, computer, and telecommunication technologies are converging into new product categories like media centres and IP telephones, but they all build on today’s technology. This in itself is not a bad thing, but the real challenge is to build products with the ability to survive in an overcrowded frequency spectrum; not only today but also tomorrow.

Today convergence is a very hot issue and new convergence technologies like UMA (Unlicensed Mobile Access) have been defined, and solutions based on the UMA standard are emerging. This technology provides alternative access to the GSM and GPRS core network services via IP-based broadband connections (like e.g. ADSL). The main rationale behind UMA is to use an unlicensed wireless technology (e.g. IEEE 802.11b/g or Bluetooth) as a transparent transport layer, and thereby implement the functionality in the mobile

network (i.e. in the mobile device and a new network element, the UMA Network Controller (UNC), which interfaces to the core GSM and GPRS network elements). Issues like interoperability and interference are very central in the system, and because the technology is based on standard access points, UMA does not eliminate one of the biggest challenges faced in a multi-technology environment, i.e. problem-free wireless co-existence. Consequently, expert knowledge within wireless communication is paramount in the successful development of robust products. Our main focus at RTX Telecom A/S is wireless links and we have devoted a lot of attention to this area in the development of robust and power efficient solutions for a wide range of big international customers. We have a long track record within wireless product development, and our solutions are spread across all of the three ISM bands (900 MHz, 2.4 GHz, and 5.8 GHz), along with standard DECT, GSM/GPRS, and TD-SCDMA. Hence, RTX Telecom A/S offers valuable knowledge within implementation of advanced wireless solutions.

Interference – overcrowding in the ISM bands requires innovative solutions

Popular Wireless Personal Area Network technologies such as Bluetooth and WLAN are designed to operate in the 2.4 GHz ISM band, and a wide range of proprietary solutions also exist in this frequency band along with e.g. microwave ovens. This sharing of the spectrum among various wireless devices operating in the same environment may lead to severe interference problems and result in significant performance degradation. To counter these problems, e.g. Bluetooth has been extended with an Adaptive Frequency Hopping (AFH) scheme, which avoids hopping to channels with a high level of interference. However, this only solves parts of the interference problem. At RTX Telecom A/S, we have implemented a wide range of DECT based solutions which are highly robust towards interference. In the design of these, we made use of our extensive experience within wireless engineering. Consequently, we know how to make effective solutions with regards to interference.

Interoperability – customer value is linked to the overall user experience

Interoperability is a very central issue in the introduction of new technologies; to  the average user, the ability of different vendors’ products to intercommunicate has a direct bearing on the perception of customer value. However, the race to be the first on the market with a new technology often results in semi-proprietary solutions. We can even see this happening today with the emergence of the new IEEE 802.11n standard. Although it is not yet fully ready, you can already buy IEEE 802.11n-based equipment.

However, even these solutions acknowledge the importance of interoperability, as they typically offer backward compatibility with IEEE 802.11b/g equipment. We also fully acknowledge the value and importance of interoperability and therefore devote a lot of attention to this area when developing solutions for our customers.

Power efficiency – new applications increase power demands

The trends within microprocessors, displays, cameras, and memory technologies open up new possibilities in embedded devices. This is especially evident in the mobile phone industry; today, a typical mid-to high end mobile phone has e.g. a Bluetooth interface, megapixel camera, colour display, and a built-in MP3 player. Consequently, power requirements have increased dramatically and power efficiency along with battery technology constitute two highly central areas in the design of new products.

Battery life, weight, and size are typical design parameters but a certain amount of trade-offs must be accepted, as these are often mutually contradicting requirements. Charging algorithms along with power management schemes are therefore also central issues in the design process, but in the end, the appropriate solutions are highly dependent on the system architecture and application area. At RTX Telecom A/S, we have experience in both making the right design choices and developing efficient power management solutions.