Communication Computer Network

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Making devices speak to each other for the purposes of communication is nothing new. Early forays into telephony such as the telegraph and telephone have since evolved into more complicated devices, and now a computer can be networked to the Internet, another PC or even a home stereo. In the early 1960s, computers had to be physically shared, making the sharing of data and other information difficult. Seeing this was not practical, researchers developed a way to “connect” the computers so they could share their resources more efficiently. Hence, the early computer network was born.

Through the then-new communication protocol known as packet switching, a number of applications, such as secure voice transmission in military channels became doable. These new circuits provided the basis for the communication technologies of the rest of the 20th century, and with further refinement these were applied to computer networks.

These networks provided the basis for the early ARPANET, which was the prototype of the modern Internet. The Advanced Research Projects Agency (ARPA) submitted the proposal for the project on June 3, 1968 which was accepted a few weeks later. This proposal entitled “Resource Sharing Computer Networks” would allow ARPA not only the further sharing of their data, but would allow them to further their research in a wide variety of military and scientific fields. After being tested in four locations, the network spread and the new protocols created for its use evolved into today's World Wide Network.

In 1977, early PC-based Local Area Networks, or LANs (Local Area Networks) were scattering and while at first restricted to academics and hobbyists, they finally found their way into the offices and in homes, although the explosion into the latter two arenas is a relatively recent phenomenon. LAN variants also developed, including Metropolitan Area Networks (MANs) to cover large areas such as a college campus, and Wide Area Networks (WANs) for university-to-university communication. With the widespread use of computers in the corporate world, the speed and convenience of using them to communicate and transfer data has forever altered the landscape of how people conduct business.

This thesis is about WiMAX, so I will give a brief introduction of WiMAX. WiMAX stands for Worldwide Interoperability for Microwave Access. It is a new telecommunications technology fundamentally aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. It is based on the IEEE 802.16 standard, which is also called Wireless MAN. The name WiMAX was formed by the WiMAX Forum, which was created in June 2001 to support conformance and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL."

When viewed as a method of data transport, wireless technology seems very similar to wired technology. You have a hardware, a method of transmission, and connections on both ends that transform data from human-intelligible to transportable and back. For both wired and wireless technology, the range of transmission is an issue. You can't move your laptop 15 feet from the wall jack when depending on a 10-foot cable. Similarly, you can't go out for a jog and expect your in-home cordless phone to keep a connection five miles away from its receiver. But if you get either a 20-foot cable or a wireless connector of sufficient power, you can move your laptop 15 feet away from the wall jack; and if you get a cellular phone, you can go jogging five miles away from your house and still take calls (as long as your service provider has a practical antenna set up).

The methods of connection and ranges of service available differ in wireless technology just as they do in wired technology. Home telephones with a wireless handset have a more restricted range than cellular phones; infrared transmissions have a lesser range than radio-wave (including microwave) transmissions. Different types of wireless solutions can communicate ten feet, ten miles, or with a satellite in orbit.

Wireless networks permit you to eliminate bundles of cables. Wireless connections give more mobility; the downside is there can sometimes be interference that might block the radio signals from passing through. One way to avoid this is by placing the source of your wireless connection in a spot where the signal will have as little interference as possible. Sometimes networks working around are using the same frequencies, and this can also cause interference within the network and can reduce its performance.

Compatibility issues also arise when working with wireless networks. Components not made by the same company may not work together, or might require extra work to fix compatibility issues. To avoid this, purchase products made by the same company so that there are fewer compatibility issues.

Wireless networks, in terms of internet connections, are slower than of those that are connected directly through an Ethernet cable. Though the speed is slower, most things will still move at the same speed except for things like video downloads. Though wireless technology is under development phase, it is now relatively easier to get networks up and running cheaper and faster than ever before.

A wireless network is more exposed because anyone can try to sneak into a network broadcasting a signal. Many networks offer WEP - Wired Equivalent Privacy - security systems which have been found to be vulnerable to intrusion. Though WEP does stop some intruders, the security difficulties have caused some businesses to stay with wired networks until security can be improved. Another type of security for wireless networks is WPA - Wi-Fi Protected Access. WPA provides more security to wireless networks than a WEP security set up. The use of firewalls will help with security breaches which can help to fix security problems in some wireless networks that are more vulnerable.

In 1997, the Institute of Electrical and Electronics Engineers (IEEE) formed the first WLAN standard. They called it 802.11 after the name of the group formed to administer its development.

Unluckily, 802.11 only supported a highest network bandwidth of 2 Mbps - too slow for most applications. For this reason, ordinary 802.11 wireless products are no longer manufactured. This standard defines the media access control (MAC) and physical (PHY) layers for a LAN with wireless connectivity. It addresses local area networking where the connected devices communicate over the air to other devices that are within close proximity to each other.

Basic Service Set: A BSS is a set of stations that communicate with one another. A BSS does not generally refer to a particular area, due to the fears of electromagnetic propagation. When all of the stations in the BSS are mobile stations and there is no connection to a wired network, the BSS is called independent BSS (IBSS). IBSS is normally short-lived network, with a small number of stations that is created for a particular purpose. When a BSS includes an access point (AP), the BSS is called infrastructure BSS.

When there is an AP, If one mobile station in the BSS must talk to another mobile station, the communication is sent first to the AP and then from the AP to the other mobile station. This put away twice the bandwidth that the same communication. While this appears to be a significant cost, the profit provided by the AP far outweigh this cost. One of them is, AP buffers the traffic of mobile while that station is operating in a very low power state

[1] Extended Service Set (ESS) A ESS is a set of infrastructure BSSs, where the APs communicate among themselves to forward traffic from one BSS to another and to facilitate the movement of mobile stations from one BSS to another. The APs perform this communication via an abstract medium called the distribution system (DS). To network equipment outside of the ESS, the ESS and all of its mobile stations appears to be a single MAC-layer network where all stations are physically stationary. Thus, the ESS hides the mobility of the mobile stations from everything outside the ESS.

Distribution System the distribution system (DS) is the mechanism by which one AP communicates with another to exchange frames for stations in their BSSs, forward frames to follow mobile stations from one BSS to another, and exchange frames with wired network.

These services are:

  • Station Services: Authentication, De-authentication, privacy, delivery of data
  • Distribution Services: Association, Disassociation, Re-association, Distribution, Integration

Station Services Similar functions to those that are expected of a wired network. The wired network function of physically connecting to the network cable is alike to the authentication and de-authentication services. Privacy is for data security. Data delivery is the dependable delivery of data frames from the MAC in one station to the MAC in one or more other station, with negligible duplication and negligible ordering.

Distribution Services provide services necessary to let mobile stations to roam freely within an ESS and permit an IEEE 802.11 WLAN to connect with the wired LAN infrastructure. A slim layer between MAC and LLC sub layer that are invoked to determine how to forward frames within the IEEE 802.11 WLAN and also how to deliver frames from the IEEE 802.11 WLAN to network destinations outside of the WLAN.

  • The association service set up a valid connection between a mobile station and an AP. It is essential for DS to know where and how to deliver data to the mobile station. The logical connection is also necessary for the AP to accept data frames from the mobile station and to assign resources to support the mobile station. The association service is invoked once, when the mobile station enters the WLAN for the first time, after the application of power or when rediscovering the WLAN after being out of touch for a time.
  • The re-association service consists of information about the AP with which a mobile station has been formerly associated. Mobile station uses repeatedly as it moves in ESS and by using re-association service, a mobile station provides information to the AP with which the mobile station was previously associated, to obtain frames.
  • The disassociation service is used to force a mobile station to associate or to inform mobile station AP is no longer available. A mobile may also use the disassociation service when it no longer require the services of the AP.
  • An AP to decide how to transport the frames it gets uses the distribution service. AP invoke the distribution service to determine if the frame should be sent back into its own BSS, for delivery to a mobile station that is linked with the AP, or if the frame should be sent into the DS for delivery to another mobile station associated with a different AP or to a network destination.
  • The integration service connects the IEEE 802.11 WLAN to other LANs. The integration service translates IEEE 802.11 frames to frames that may traverse another network, and vice versa.

[1] The IEEE 802.11 standard states that each station must maintain two variables that are dependent on the authentication, de-authentication services and the association, re-association, disassociation services. The variables are authentication state and association state and used in a simple state machine that determines the order in which certain services must be invoked and when a station may begin using the data delivery service. A station may be authenticated with many different stations simultaneously. However, a station may be associated with only one other station at a time.

Since the initial establishment of the 802.11 standard working group, it has been extended with numerous task groups, designated by the letters a through i. Groups a, b, and c have completed their tasks, and the results amended to the original standards. The details of each task group are listed below.

While 802.11b was in development, IEEE created a second extension to the original 802.11 standard called 802.11a. Since 802.11b gained in popularity much faster than did 802.11a, some people believe that 802.11a was created after 802.11b. In fact, 802.11a was created at the same time. Due to its higher cost, 802.11a is usually found on business networks whereas 802.11b better serves the home market.

802.11a supports bandwidth up to 54 Mbps and signals in a regulated frequency spectrum around 5 GHz. This higher frequency compared to 802.11b shortens the range of 802.11a networks. The greater frequency also means 802.11a signals have more difficulty penetrating walls and other obstructions.

Since 802.11a and 802.11b utilize different frequencies, both technologies are incompatible with each other. Some vendors offer hybrid 802.11a/b network gear, but these products merely implement the two standards side by side (each connected devices must use one or the other).

IEEE 802.11a-1999 or 802.11a, is an amendment to the IEEE 802.11 specification that added a greater throughput of up to 54 Mbit/s by using the 5 GHz band. It has seen worldwide implementation, especially from within the corporate world. The amendment has been incorporated into the published IEEE 802.11-2007 standard. 802.11 is a set of IEEE standards that govern wireless networking transmission methods. They are commonly used now a day in their 802.11a, 802.11b, and 802.11g versions to provide wireless connectivity in the home, office and some commercial establishments. The 802.11a amendment to the original standard was ratified in 1999. The 802.11a standard uses the same core protocol as the original standard, operates in 5 GHz band, and uses a 52-subcarrier orthogonal frequency-division multiplexing (OFDM) with a maximum raw data rate of 54 Mbit/s, which yields realistic net achievable throughput in the mid-20 Mbit/s. The data rate is reduced to 48, 36, 24, 18, 12, 9 then 6 Mbit/s if required. 802.11a originally had 12/13 non-overlapping channels, 12 that can be used indoor and 4/5 of the 12 that can be used in outdoor point to point configurations. Recently many countries of the world are allowing operation in the 5.47 to 5.725 GHz Band as a secondary user using a sharing method derived in 802.11h. This will add another 12/13 Channels to the overall 5 GHz band enabling significant overall wireless network capacity enabling the possibility of 24+ channels in some countries. 802.11a is not interoperable with 802.11b as they operate on separate bands, except if using equipment that has a dual band capability. Nearly all enterprise class Access Points have dual band capability.

IEEE extended on the basic 802.11 standard in July 1999, creating the 802.11b. 802.11b supports bandwidth up to 11 Mbps, like traditional Ethernet.

802.11b uses the same unregulated radio signaling frequency (2.4 GHz) as the original 802.11 standard. Vendors often favor using these frequencies to lower their production costs. Being unregulated, 802.11b gear can incur interference from microwave ovens, cordless phones, and other appliances using the same 2.4 GHz range. However, by installing 802.11b gear a reasonable distance from other appliances, interference can easily be avoided.

IEEE 802.11b-1999 or 802.11b, is an amendment to the IEEE 802.11 specification that extended throughput to up to 11 Mbit/s using the same 2.4 Ghz band. This specification under the marketing name of Wi-Fi has been implemented worldwide. The amendment has been accommodated into the published IEEE 802.11-2007 standard.

802.11b has a maximum raw data rate of 11 Mbit/s and uses the same CSMA/CA media access method defined in the original standard. Due to the CSMA/CA protocol overhead, in practice the maximum 802.11b throughput that an application can achieve is about 5.9 Mbit/s using TCP and 7.1 Mbit/s using UDP.

802.11b products appeared on the market in early 2000, since 802.11b is a direct extension of the DSSS - Direct-sequence spread spectrum, modulation technique defined in the original standard. Technically, the 802.11b standard uses Complementary code keying (CCK) as its modulation technique. The sudden increase in throughput of 802.11b (compared to the original standard) along with simultaneous substantial price reductions led to the speedy acceptance of 802.11b by the users as the definitive wireless LAN technology.

802.11b is used in a point-to-multipoint configuration, wherein an access point communicates through an omni-directional antenna with one or more nomadic or mobile clients that are located in a coverage area around the access point. Typical indoor range is 30 m (100 ft) at 11 Mbit/s and 90 m (300 ft) at 1 Mbit/s. The overall bandwidth is dynamically demand shared across all the users on a channel. With high-gain external antennas, the protocol can also be used in fixed point-to-point arrangements, especially at ranges up to 8 kilometers (5 miles) although some report success at ranges up to 80-120 km (50-75 miles) where line of sight can be established. This is usually done in place of costly leased lines or very cumbersome microwave communications equipment.

802.11b is a half duplex protocol - it can send OR receive, meaning not both at the same time, only one at a time. In addition, it uses the same 2.4 GHz range as many cordless phones so plenty of opportunity exists for interference. Use 900 MHz cordless phones if using 802.11b in the same area.

IEEE 802.11g-2003 or 802.11g is an amendment to the IEEE 802.11 specification that extended throughput to up to 54 Mbit/s using the same 2.4 GHz band as 802.11b. This specification under the marketing name of Wi-Fi has been implemented worldwide.

802.11g was the 3rd modulation standard for Wireless LAN. It works in the 2.4 GHz band (like 802.11b) but works at a maximum raw data rate of 54 Mbit/s, or about 19 Mbit/s net throughput (identical to 802.11a core, except for some additional legacy overhead for backward compatibility). 802.11g hardware is fully backwards compatible with 802.11b hardware. Details of making b and g work well together occupied much of the lingering technical process. In an 11g network, however, the presence of a legacy 802.11b participant will reduce the speed of the overall 802.11g network big time. The modulation scheme used in 802.11g is orthogonal frequency-division multi-plexing (OFDM) copied from 802.11a with data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbit/s, and reverts to CCK (like the 802.11b standard) for 5.5 and 11 Mbit/s and DBPSK/DQPSK+DSSS for 1 and 2 Mbit/s. Even though 802.11g works in the same frequency band as 802.11b, it can achieve higher data rates because of its heritage to 802.11a.

The then-proposed 802.11g standard was speedily accepted by users starting in January 2003, well before ratification, due to the desire for higher speeds, and reductions in manufacturing costs. By summer 2003, most dual-band 802.11a/b products became dual-band/tri-mode, supporting a and b/g in a single mobile adapter card or access point. Despite its major acceptance, 802.11g suffers from the same interference as 802.11b in the already crowded 2.4 GHz range. Devices operating in this range include: microwave ovens, Bluetooth devices, baby monitors and (in the USA) digital cordless telephones which can lead to interference issues. Further the success of the standard has caused usage/density problems related to crowding in urban areas. This crowding can cause a dissatisfied user experience as the number of non-overlapping usable channels is only 3 in FCC nations or 4 in European nations.

802.11n is an emerging standard for high-speed Wi-Fi networking. 802.11n offers throughput more than 100 Mbps and is diffidently destined to wipe out all of the existing 802.11a, 802.11b and even 802.11g Wi-Fi standards, someday. The newest IEEE standard in the Wi-Fi category is 802.11n. It was designed to improve on 802.11g in the amount of bandwidth supported by utilizing multiple wireless signals and antennas (called MIMO technology) instead of one. When this standard is finalized, 802.11n connections should support data rates of over 100 Mbps. 802.11n also offers somewhat better range over earlier Wi-Fi standards due to its increased signal intensity. 802.11n equipment will be backward compatible with 802.11g gear. Plus points of 802.11n are fastest maximum speed and best signal range; more resistant to signal interference from outside sources Cons of 802.11n are standard is not yet finalized; costs more than 802.11g; the use of multiple signals may greatly interfere with nearby 802.11b/g based networks.

802.11n will work by utilizing more that one wireless antennas in tandem to transmit and receive data. The term MIMO (Multiple Input, Multiple Output) refers to the ability of 802.11n and similar technologies to organize several simultaneous radio signals. MIMO increases both the range and throughput of a wireless network. An extra technique employed by 802.11n involves increasing the channel bandwidth. As in 802.11a/b/g networking, each device uses a preset Wi-Fi channel on which to broadcast. Each 802.11n channel will use a larger frequency range than these earlier standards, also increasing data throughput. Once finalized, 802.11n will carry bandwidth larger than 100 Mbps and maybe even greater than 200 Mbps. Some manufacturers offer pre-N wireless equipment based on preliminary drafts of the standard. On the other hand, this equipment may not be fully compatible with 802.11n equipment that will meet the final standard.

802.11n builds on previous 802.11 standards by adding multiple-input multiple-output (MIMO) to the physical (PHY) layer. MIMO uses multiple transmitter and receiver antennas to improve the system performance. The transmitter and receiver use precoding and post coding techniques, respectively, to gain the capacity of a MIMO link. Precoding includes spatial beamforming and spatial coding, where spatial beamforming improves the received signal quality at the decoding stage. Spatial coding can increase data throughput via spatial multiplexing and increase range by exploiting the spatial diversity, through techniques such as Alamouti coding. The number of antennas relates to the number of simultaneous streams: two receivers and two transmitters (2x2) or four receivers and four transmitters (4x4). The standards requirement is a 2x2 with a maximum two streams, but allows 4x4.

IEEE 802.11y is a proposed amendment to the IEEE 802.11 standard that will allow for Wi-Fi like equipment to operate on a secondary basis in licensed frequency bands.

In June of 2007 the FCC issued final rules for a novel "lite licensing" scheme in the 3650-3700 MHz band Licensees pay a small fee for a nation wide, non-exclusive license. They then pay an additional nominal fee for each high powered base station that they deploy. Neither the client devices (which may be fixed or mobile), nor their operators require a license, but these devices must get an enabling signal from a licensed base station before transmitting. All stations must be identifiable in the event they cause interference to incumbent operators in the band. Furthermore, there is a requirement that multiple licensees' devices are given the opportunity to transmit in the same area using a "contention based protocol" when possible. If interference between licensees, or the devices that they have enabled, cannot be mediated by technical means, licensees are required to resolve the dispute between them. The US 3650MHz rules allow for registered stations to keep working at much higher power than traditional Wi-Fi gear (Up to 20 watts equivalent isotropically radiated power). The combination of higher power limits and enhancements made to the MAC timing in 802.11-2007, will allow for the development of standards based 802.11 devices that could operate at distances of 5km or more. IEEE 802.11y adds three new concepts to 802.11-2007. Contention based protocol (CBP) - enhancements have been made to the carrier sensing and energy detection mechanisms of 802.11 in order to satisfy the FCC's requirements for a contention based protocol. Extended channel switch announcement (ECSA) - provides a mechanism for an access point to notify the stations connected to it of its intention to change channels or to change channel bandwidth. This mechanism will allow for the WLAN to regularly pick the channel that is the least noisy and the least likely to cause interference. This mechanism will also be used in 802.11n, which will allow devices to switch between .11y operation and .11n operation in the 2.4 and 5 GHz bands. Dependent station enablement (DSE) - is the mechanism by which an operator extends and retracts permission to license exempt devices (referred to as dependent STAs in .11y) to use licensed radio spectrum. Fundamentally, this process satisfies a regulatory requirement that dictates that a dependent STAs operation is contingent upon its ability to receive periodic messages from a licensee's base station, but DSE is extensible to other purposes in regards to channel management and coordination.

The enabling station (aka the licensee's base station) may or may not be the access point that the dependent STA connects to. In fact, an enabling station may enable both an access point and its clients. Also, although the dependent STAs are required by regulation to receive information from the enabling station over the air, they are not required transmit over the air to complete the DSE process. A dependent STA may also connect to a nearby Access Point for a short period of time and use the internet or some other means to complete the channel permissioning process with the enabling station. This flexibility lessens the likelihood of a dependent STA causing interference while trying to connect to a far off enabling station. The privacy and security of end users are ensured while, at the same time, licensees will have the information necessary to resolve disputes. All .11y devices transmit a rare identifier for resolving interference. The high powered fixed stations and enabling stations transmit the location that they are operating from as their unique identifier. This location is also registered in an FCC database that will identify the licensee. The dependent STAs transmit the location of the station that enabled it plus a unique string supplied by the enabling station. This ensures that the responsible party, the licensee, is contacted to resolve disputes. This mechanism also alleviates the problems associated with having the dependent STA broadcasting its location. Requiring all devices to have GPS or some other means of verifying their location would increase the cost and complexity of devices, and this solution may be inadequate indoors. This method also resolves fears that mobile devices that constantly beacons its location could be used inappropriately by third parties to track a user's location. For most of applications, 802.11b, which work at 2.4 GHz, is enough.  It is the most widely adopted standard of the previous three, and is most deployed.  The price of 802.11b equipment is also the cheapest, due to the demand of 802.11g.  The distance of 802.11b will rely mostly on whether or not the communicating devices have line of site or not.  The less obstacles in between the transmitting and receiving devices, the better the wireless connection will be, which translates to better web surfing. If you are using your wireless router/access point only for internet then this wireless standard is best for you.  This is because your connection to the internet through your broadband modem is only operating at best about 2mbps (depending on your service area), which is still very fast.  Your 802.11b devices can transfer data up to 11mbps, which is therefore sufficient for internet use.

802.11g is taking place of the generally accepted 802.11b standard, due to the fact that the frequency on which it operates is the same, and price has dramatically gone down on products.  Like the 802.11b devices, products using this standard will usually need line of site, to function at optimal performance.

802.11b and 802.11g both work under the 2.4ghz frequency range.  It means that they both are inter-operable with each other.  All 802.11g devices can talk to 802.11b devices.  The advantage of 802.11g is that you will be able to transfer files between computers or networks at much faster speeds. If you are using your wireless connection to move files around the home or office, you should go with the 802.11g.  With the home audio and theater moving to wireless networks, you want to be sure to have an 802.11g network setup in your home. This standard also allows for some manufactures to have devices working at speeds up to 108mbps, which is suggested if you plan to transfer large data or audio files within your LAN.

With 802.11a, having a different frequency then 802.11b and 802.11g, it is used mostly in backhaul applications, like long distance building to building links, and Wireless Bridge Connections. It has a higher frequency, so line of site is not depended on as much as 2.4 GHz, but it also does not go as far without high gain antennas. This standard can broadcast at speeds up to 54mbps, but the equipment will cost more then 802.11b and 802.11g equipment.  One of the benefits is that you can use 802.11a in combination with 802.11b/g.  This is because the frequencies are dissimilar, hence allowing 802.11a(5ghz) to operate in a crowded 2.4ghz range.

Comparison of 802.11b and 802.11a in tabular form is:

IEEE 802.11b

IEEE 802.11a

Time Table

Standard in 1997, Products in 2000

Standard in 2001, products in 2002

Frequency Band and bandwidth

Transmit at 2.4 GHz -  IEEE 802.11g standard increases speed of 802.11b to 22 Mbps in the same 2.4 GHz band

5 GHz


11 Mbps (Effective speed - half of rated speed)

54 Mbps (Effective speed - 50% rated speed)

Modulation Technique

Spread Spectrum

OFDM (Orthogonal Frequency Division Multiplexing

Distance Coverage

Up to 300 feet

60 feet - speed goes down with increased distance

Number of access points required

Every 200 feet in each direction

Every 50 feet;


More matured products

Less matured but progressing fast

Market Penetration

Quite widespread

Just starting in 2002

Interference with other devices

Band is more polluted - major interference here

Less interference because of few devices in this band


Present problems  likely to be resolved in future

Problems now but expect resolution soon


Cheaper - $300 for access point and $75 for adapter

Expensive $ (500 in 01/2002 - will come down


Major vendors in both camps

Summary of all of the standards is:


Release Date

Op. Frequency

Throughput (Typ)

Data rate (Max)

Modulation Technique

Range (Radius Indoor)

Depends, # and type of walls

Range (Radius Outdoor)

Loss includes one wall



2.4 GHz

0.9 Mbit/s

2 Mbit/s

~20 Meters

~100 Meters



5 GHz

23 Mbit/s

54 Mbit/s


~35 Meters

~120 Meters



2.4 GHz

4.3 Mbit/s

11 Mbit/s


~38 Meters

~140 Meters



2.4 GHz

19 Mbit/s

54 Mbit/s


~38 Meters

~140 Meters


June 2009 (est.)

2.4 GHz 5 GHz

74 Mbit/s

248 Mbit/s

~70 Meters

~250 Meters


June 2008 (est.)

3.7 GHz

23 Mbit/s

54 Mbit/s

~50 Meters

~5000 Meters

The future of wireless networking is WiMAX. Wireless technology is being introduced quickly in places like China and India that have lack of copper wire and fiber cable infrastructures. Yet, there have been some genuine concerns over the use of wireless in broadband networking from a technical point of view. Some of the principal concerns have been packet loss, atmospheric intrusion, and conflict with other wireless services. The 802.16 standard deal with these concerns with QoS (Quality of Service). In short, giving more bandwidth to the right channels at the right time can reduce latency and jitter.


[1] Mustafa Ergen, “IEEE 802.11 Tutorial”, University of California Berkeley, June 2002