Much has been written lately about the expansion of 3G networks in Asia,
Europe, and the Americas. Asia, for example, has been zealous in its
adoption of next-generation wireless services. In Europe and the Americas,
though, the deployment of 3G networks hasn't been as swift. Ongoing flattening or even declining capital expenditure spending has
slowed network deployment and will prevent the implementation of 3G services until a predictable quality of service can
be guaranteed.
One of the most significant challenges service providers face
is consumer demand for 3G wireless networks that match the
performance, quality, and cost of wired networks, where bandwidth is virtually unlimited and cost is continuously decreasing.
PUSHING THE LIMITS
The industry has come a long
way since early GSM networks supported 12-kbit/s data rates.
HSDPA networks promise 5 to 15 Mbits/s. Additionally, Super
3G and WiMAX are expected to reach upwards of 100 Mbits/s.
Yet the Shannon limit, first published in 1948 by Claude Shannon, places constraints on capacity in a wireless Gaussian
Noise limited channel.
Initial WiMAX deployments will operate using larger channel
bandwidths at the expense of in-building signal penetration. As
the frequency used is increased, buildings become much more
reflective, requiring a direct line of sight to the antenna. To
increase the number of bits/second/Hz, the signal power must
be increased, or the interference must be decreased.
Other issues need to be considered, such as distance to the
user and channel delay. But the bottom line is that there is a
tremendous need for better coding, higher efficiency and linearity, improved processing speeds, and multiple antenna arrangements such as multiple-input, multiple-output (MIMO).
Operators also are experiencing a decline in the average revenue per user (ARPU), driven by the rising costs of network
deployment and pressure from consumers to offer enhanced
services without increasing the price of service contracts.
Demand for versatile yet cost-effective 3G infrastructure
solutions is on the rise in Europe and the Americas. Still, network operators realize that wholesale replacement of equipment with each new technology doesn't make business
sense, as deployed hardware needs to be upgradeable and
standards-based.
The industry hasn't quite reached the plug-and-play stage.
But recent initiatives such as OBSAI (Open Basestation Architecture Initiative) and CPRI (Common Public Radio Interface)
have made significant progress toward the vision of modular, scalable, and upgradeable equipment.
For example, when the processing end of the basestation
is centrally located, the RF transmitter and receiver can be located on top of abuilding and distributed overfiber and coaxial cable for maximumcoverage or deployed at street level formaximum effectiveness. This gives networkoperators two or more options tomeet various coverage andcapacity requirements.
MORE SOLUTIONS
To further reduce expenditures
and fast-track the delivery of the next-generation wireless
services consumers demand today, service providers can
select infrastructure solutions that support the remote adjustment of individual parameters such as antenna tilt, azimuth,
and link power to reduce dropped or blocked calls and maximize data throughput.
Remote adjustment reduces on-site servicing. It also helps
service providers track variations in user patterns and remotely
adjust capacity requirements when periodic increases in network traffic occur.
The lesson to be learned? Network operators mustn't lose
hope. They are closer than they think to achieving the goal of
delivering cost-effective next-generation wireless services.