Technical Challenges for Broadband Wireless

the technical challenges of developing and deploying a successful broadband
wireless system. The discussion presented in this section sets the stage for the rest of the
book, especially Part II, where the technical foundations of WiMAX are discussed in detail.
To gain widespread success, broadband wireless systems must deliver multimegabit per second
throughput to end users, with robust QoS to support a variety of services, such as voice,
data, and multimedia. Given the remarkable success of the Internet and the large variety of
emerging IP-based applications, it is critical that broadband wireless systems be built to support
these IP-based applications and services efficiently. Fixed broadband systems must, ideally,
deliver these services to indoor locations, using subscriber stations that can be easily selfinstalled
by the enduser. Mobile broadband systems must deliver broadband applications to laptops
and handheld devices while moving at high speeds. Customers now demand that all this be
done without sacrificing quality, reliability, or security. For WiMAX to be successful, it must
deliver significantly better performance than current alternatives, such as 3G and Wi-Fi. This is
indeed a high bar.
Meeting these stringent service requirements while being saddled with a number of constraints
imposed by wireless make the system design of broadband wireless a formidable technical
challenge. Some of the key technical design challenges are
• Developing reliable transmission and reception schemes to push broadband data through a
hostile wireless channel
• Achieving high spectral efficiency and coverage in order to deliver broadband services to a
large number of users, using limited available spectrum
• Supporting and efficiently multiplexing services with a variety of QoS (throughput, delay,
etc.) requirements
• Supporting mobility through seamless handover and roaming
• Achieving low power consumption to support handheld battery-operated devices
• Providing robust security
• Adapting IP-based protocols and architecture for the wireless environment to achieve
lower cost and convergence with wired networks
As is often the case in engineering, solutions that effectively overcome one challenge may
aggravate another. Design trade-offs have to be made to find the right balance among competing
requirements—for example, coverage and capacity. Advances in computing power, hardware
miniaturization, and signal-processing algorithms, however, enable increasingly favorable tradeoffs,
albeit within the fundamental bounds imposed by laws of physics and information theory.
Despite these advances, researchers continue to be challenged as wireless consumers demand
even greater performance.


COMMENT Uncategorized

  1. Valentina

    Wifi refers to an Internet intoecncon over a short distance radio signal put out by a wireless router or access point. This is what you normally find in your home. Other then the cost of having the Cable or DSL Internet brought to your house, you do not pay anything more for it. You produce the signal with your own router. It has a range of about 150 feet. This is used in coffee shops and malls because of its short range. It forces you to come into the shop to use it (and maybe you will buy something).Mobile Broadband runs on the cell phone network. Anywhere your cell phone works, so will your Internet. And just like you can get into your car and drive across the country and your cell phone will continue to work by switching from tower to tower, so will your computer. You can use it almost anywhere.However, the bandwidth needed for a computer is many times more than for a cell phone. And so the cell companies charge you a price that matches that usage. People who are unaware have accidentally run up bills in the thousands of dollars in a single month using their mobile intoecncon to run the computer for more than a few minutes. Check with your cell phone proivide and they can give you information on Mobile Broadband. But at this time the technology is still beyond most user’s price range.Mobile Broadband is also used for the limited Internet intoecncon you can get on most cell phones. But that is not a intoecncon with the speed or power needed to run a full computer.VA:F [1.9.12_1141](from 0 votes)

  2. Guru

    Describes a communications medium capable of transmitting a relatively large amount of data over a given period of time. A descriptive term for evolving digital technologies that offers integrated access to voice, high-speed data service, video-demand services, and interactive delivery services.

    Broadband PCS
    Personal communications services created in the A- through F-Block auctions and used for voice and data. Broadband PCS is allocated 140 MHz of spectrum with 20 MHz currently unassigned. Frequency blocks A, B, and C were each assigned 30 MHz of spectrum, while frequency blocks D, E, and F were each assigned 10 MHz of spectrum.