What is Inside WiMAX Technology (802.16)

by Shafqat Zia

WiMAX technology is identified as Worldwide Interoperability for Microwave Access; it is formed in June 2001 to encourage conformance and interoperability of the WiMAX (IEEE 802.16) standard, officially known as Wireless Metropolitan Area Network (WMAN). WiMAX technology intended to offer wireless data in a related fashion as compare to WiFi but on a outsized level and speed, therefore building national wireless networks with ease.

The driving forces behind WiMAX technology are link-to-multilink microwave networks from organizations for instance Alcatel and Siemens stay alive for years. Alternatively WiMAX offers a consistent technology according to its standard. WiMAX technology open loom could let product manufacturers make revenues of scale via producing number of WiMAX products & components to single IEEE 802.16 standard, this also allow component manufacturers buy low-cost, standards compliant components from rival component providers. This would defiantly help existing wireless service providers.

In addition, service providers lacking a mobile network can start a WiMAX technology network at comparatively stumpy price. WiMAX technology would also allow interoperability among different systems. WiMAX technology will offer high data speed network connections and in this manner serve as a backhaul for WiFi LAN (WLAN) hot spots, where people on the move can access carriers' WiFi services on mobile technology basis. WiMAX technology possibly will offer a much cheaper, easier to build network infrastructure other than the physical medium of WiFi backhauls that cable, T1 or DSL systems presently offer. These issues, together with user's requirements for broadband facilities, will offer the grounds to markets to grow with WiMAX and wireless-broadband. However, the WiMAX technology faces some solid challenges ahead of it can become commonly accepted by users.

Because WiMAX is based on IEEE 802.16 Standard and HiperMAN, the IEEE and ETSI have each become accustomed it's standard to take in many of the other's essential characteristics. IEEE 802.16 standard partitioned its MAC (Medium Access Control) layer into sub-layers that hold some different transport equipments and technologies, together with Ethernet, IPv4, IPv6 and other asynchronous transfer mode. This allows traders to use WiMAX technology it doesn't matter about what technology they support for transmission. WiMAX technology has a wide communication range up to 50 kilometres because principles allows WiMAX network to transfer data at higher rates and because of this move towards use of directional antennas that generates persistent radio signals. WiMAX base station provide service to only 500 users at a time not more than that just because to they are sharing bandwidth and this factor may result in lower date rates among. Technically every single station will possibly provide communication an area inside a 10 miles radius. On the other hand WiFi has a range of only a few hundred feet while other third generation mobile networks have the range of few thousand feet.

As compare to other wireless standards their address broadcastings over particular frequency range, WiMAX network allocates data communication over several broad signal frequency ranges. The capacity to work in several ranges makes the most of the technology's ability to communicate above the frequencies that will evade interference with other wireless network applications. WiMAX system's communication date rate and range differ a lot depending on implementation usage of frequency bands. These advantages of flexibility allow providers to employ different frequencies that depend on the speed and range needed for a particular data communication. The WiMAX technology attains higher data transmission rates in part by OFDM (Orthogonal Frequency Division Multiplexing). OFDM amplifies data capacity and bandwidth via dividing broad capacity channels to many narrowband channels; every channel uses different frequencies that can transmit different pieces of a message at the same time.

The spaces between channels are extremely close mutually other than avoiding intervention as nearby channels are orthogonal to each other and therefore no overlapping between them. The primary IEEE 802.16 standard uses the 10 to 66 GHz frequency range. On those higher frequencies WiMAX network needed a straight line of sight among senders & receivers. This factor shrinks the multi path distortion that arises when transmitting signals not follow the line of sight echoed of outsized items and finish off out of organization, in this manner jumbling the inbound communication and reducing bandwidth. Dropping multi path distortion could therefore enhance the bandwidth. In theory WiMAX network can offer single channel data rates up to 75 Mbits/s equally on the downlink and uplink. Service providers can use several 802.16 channels for single broadcast to offer bandwidths of up to 350 Mb per second.

The accepted IEEE 802.11b WiFi WLAN technology data rate are limited to 11Mbps, on the other hand newer 802.11a and 802.11g provide upto 54Mbps in favourable conditions but practically all of the them transmit at lesser speed. Third generation mobile network technologies will support around 115 Kbps.

As far as security is concerned in WiMAX technology it uses PKI (Public Key Infrastructure) authentication, which transmit via digital certificates by identifying parties over trusted authorities. The IEEE 802.16 system encrypts data by using 56 bit DES (Data Encryption Standard) keys. In the meantime WiMAX network is extremely scalable as it is simple to include broadcast channels to offer extra bandwidth as required.

The expenditure of setting up wireless technology is significantly increases when the wireless services are supplied at higher frequencies as the line of sight constraints required the setting up of further antennas to cover up the equivalent geographical area. The available frequencies for new wireless standards such as IEEE 802.16 are normally higher as some of the other wireless technologies are more sought-after to lower ranges that have been approved for other use.

During the development of WiMAX technology, the WiMAX Forum has strongly supported and encourage the WiMAX technology, which involves a cluster of commercial leaders such as AT&T, Cisco, Samsung, Intel, and some others giants. The WiMAX forum group's workforce is comprised of many working groups that highly focused on regulatory, marketing, technological characteristics. WiMAX product certification program was extended by the certification working group which intends to certify interoperability among WiMAX products from manufacturers internationally. More on Free WiMAX Info

About the Author

S Zia is the technical editor of Articles on Mobile Computing & Wireless Technologies also Author of http://www.freewimaxinfo.com

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Increasing Notebook Battery Power

Depending upon the model, a notebook battery usually lasts from 1 to 8 hours. However, with efficient battery usage, an hour or two of battery power can significantly be increased. You can save battery power by using the built-in battery saving modes and by following good notebook battery-saving practices.

Built-in battery-saving modes are Stand By and Hibernate. In the Stand By mode, open applications are stored in the RAM, the hard disks power down, the monitor switches off, but the processor goes on running. When you again perform some activity of the mouse or the keyboard, then the hard disk powers up, the monitor switches on, and the data from the RAM is activated, restoring your notebook exactly the way you left it.

The Hibernation mode is used when the notebook is left unattended for a long time. The open applications are stored on the hard disk, which subsequently powers down, the monitor turns off, and the processor turns off going in for hibernation. On soft rebooting like a restart or wake up on LAN, the processor turns on, the laptop wakes up, and the same exact settings are restored. Both these modes should be used to conserve battery power. You can preset your preferences in the settings of your notebook, so that in case you doze off, or leave the device for a coffee or a snack, the notebook automatically goes into any one of these power saving modes.

Following battery-saving practices can also save notebook battery power. You should always adjust the monitor controls to suit the room lighting conditions. Dimming the contrast and brightness saves battery power besides providing relief to your eyes. Auto-save and auto-update features of applications start in the background without your knowledge and these should be disabled. External devices consume a lot of battery power, hence the usage of external mice, monitors, keyboards, optical drives, videocam, digital cameras, or any other device connected to the PC Card slot, VGA/ FireWire/ USB port should be avoided.

Increase the RAM memory, if an extra slot is available, as this puts fewer burdens on the hard disk, which consumes a lot of battery power. Avoid multimedia games while you are running your notebook on battery power. Similarly, avoid music or movies. Copy the CD/DVD on the hard disk and play it from there, instead of the optical drive. Disable WiFi and Bluetooth. Built-in wireless cards should also be disabled. Decrease or set to mute the notebook speaker volume. Turn off all preprogrammed scheduled tasks. All unused open applications should be closed. The general guideline is that when your notebook is on battery power, you should perform only such operations, which are the need of the hour. Rest of the applications can be performed, when your notebook is connected to the mains.

Keeping good care of the battery also prolongs its life. To maximize performance of nickel-metal hydride batteries, they have to be completely drained off before they are recharged. However, lithium-ion batteries do not need cycling/ conditioning, and they do not suffer from memory effects. Hence, they need not be fully drained off before recharging. When the notebook is not in use for an extended period, the battery pack should be removed to avoid battery leakage. Before removing the battery pack, you should charge it fully and then remove it, as all kinds of batteries should always be stored in a fully charged state. Do not store your battery pack along with metal parts, as this will short-circuit your battery.

Utilizing the built-in battery saving options and other means, you can significantly add one to three hours more in the total capacity of your notebook battery. Sometimes, in critical situations, like an important meeting, this extra hour of notebook battery power can help you clinch your desired deal.

This article is under GNU FDL license and can be distributed without any previous authorization from the author. However the author's name and all the URLs (links) mentioned in the article and biography must be kept.

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Steps to Secure Your Wireless LAN

by Gavin Sanderson

It is the duty of technology not only to improve itself, but to become more and more user friendly. We can see this happen within the ever evolving sphere of Wireless LAN connections. Here the only constant is the easy to install, plug and play hardware which is well complimented by simple user friendly software. One only has to plug in the device to explore the network or even the Internet, however, Wireless LAN connections are often vulnerable to hackers or even virus threats. These malicious entities try to infiltrate the network and destroy important data. Then again, there is good news for all those people who wish to secure their Wireless LAN connections. Now you can enjoy the benefits of a protected Wireless LAN experience for less than a hundred dollars.

The first step after installing the hardware is to work out the configuration best suited for your network. Pay close attention to the security settings in particular and do not enable the Wireless LAN before you have everything in place and configured. After all, it is better to be safe than sorry. There are a few safety precautions one can adopt after setting up the Wireless LAN network.

Let us begin with the router and the access points. We recommend that you deploy an administrator password to reinforce and bolster access routes. In this way, the intruder will not be able to log into your Wireless LAN system without entering the correct password. Then again, certain systems or devices are preconfigured with default passwords.

Unfortunately, these passwords are often the manufacturer's own name, because it is easy to remember although it lacks originality. We know that leaving a network unguarded with default passwords is the fool hardy option. This is why we must customize all the access points and the wireless router with our own unique passwords. Often we forget these passwords since we do not need to use them on a regular basis. At this point there is no option but to revert back to the default settings to reenter your network. The only problem is that all your time spent on customization will go to waste as those change are erased when default settings are applied.

Remember that the access points and the routers are specifically configured to retain and protect vital information like the SSID (Service Identifier) and even the name of the Wireless LAN network. This system makes it difficult to identify our own network, but thankfully, it doesn't compromise the security. Without this elaborate masking system, you could be leaking away important details or clues that prove handy to outsiders with ill-intentions.

Now we study the two types of encryption employed to secure a Wireless LAN system. They are WEP or Wired Equivalency Privacy and the WPA or WiFi Protected Access. We know that the WEP system is widely used but it also has a sequence of easy to exploit weaknesses because of its poorly designed encryption software. On the other hand, there is the highly recommended WPA option which reinforces your network while proving surprisingly easier to install and configure. One should note that unlike WEP, WPA is not inhibited by a limited number of password combinations as it explores the keyboard beyond the alphabets and number keys. There is a preloaded WPA support system within the Windows XP software package. WPA2 is the next generation WPA, which provides greater security but relies on specially downloaded updates.

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Read more about wireless network installation and know all there is to know about wireless networking.

source:www.goarticles.com

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