DIFFERENCE BETWEEN WIMAX (WORLDWIDE INTEROPERABILITY FOR MICROWAVE ACCESS) AND Wi-Fi (WIRELESS FIDELITY)

Transcription

1 DIFFERENCE BETWEEN WIMAX (WORLDWIDE INTEROPERABILITY FOR MICROWAVE ACCESS) AND Wi-Fi (WIRELESS FIDELITY) 1 Deepa Solanki, 2 Santosh Upadhyay 1 Scholar, Department of Computer Science, Mewar University, India -deepasolanki2008@gmail.com 2 Assistant Professor, Department of Computer Science, Mewar University, India ABSTRACT-- Wireless Local Area Network (WLAN) that uses the IEEE standard and WiMAX (Worldwide Interoperability for Microwave Access) that uses the IEEE standard are networks that we are want to explore. description of the existing wireless technology Wi-Fi and WiMAX, and try to compare Wi-Fi (IEEE ) and WiMAX (IEEE ). Wireless Local Area Network (WLAN) uses of IEEE standard. WiMAX has been developed by 10 years ago, but it is still unknown by most of the people. WiMAX (Worldwide Interoperability for Microwave Access) is a 4th generation cellular telecommunication technology on working IEEE e standard. This paper has been introducing these two technologies and makes comparisons between WiMAX and WiFi. Keywords: WiMAX, Wi-Fi, QoS, OFDMA, Wireless Access Point. 1. INTRODUCTION WiMAX is based on a very flexible and robust air interface defined by the IEEE group. The aim of WiMAX to provide lastmiles broadband to a metropolitan access network which will WiMAX supports a number of advanced signal-processing techniques to improve overall system capacity[1]. It is a developed standard for Broadband Wireless Access (BWA) in fixed and mobile network. In terms of coverage, WiMAX can provide services up to 20 or 30 miles away from the based station. In WiMAX, Base Station (BS) has the responsibility to centrally control the subscriber Station (SSs). It means, the SSs have to communicate with each other through BS. A s in WiMAX is not design to clash with Wi-Fi, but it is designed to coexist with Wi-Fi. WiMAX service is measured in square kilometers while Wi-Fi is measure in square meters. There are two variants of the WiMAX standard, which are fixed and mobile WiMAX. Wi-Fi (short for "wireless fidelity") is the popular term for a high-frequency wireless local area network (WLAN). Wi- Fi is specified in the b specification from the Institute of Electrical and Electronics Engineers (IEEE) and is part of a series of wireless specifications together with , a, and g. All four standards use the Ethernet protocol and CSMA/CA (carrier sense multiple access with collision avoidance) for path sharing. The b (Wi-Fi) technology operates in the 2.4 GHz range offering data speeds up to 11 megabits per second. The modulation used in has historically been phase-shift keying (PSK). The modulation method selected for b is known as complementary code keying (CCK), which allows higher data speeds a nd is less susceptible to multipathpropagation interference[2]. This paper aimed to analyses based on fixed, portable and mobile WiMAX and Wi-Fi networks. 2. OVERVIEW OF Wi-Fi & WIMAX Introduction to Wi-Fi ( or WiFi) The IEEE specification (ISO/IEC ) is an international standard describing the characteristics of a wireless local area network (WLAN). The name Wi-Fi (short for "Wireless Fidelity", sometimes incorrectly shortened to WiFi) corresponds to the name of the certification given by the Wi-Fi Alliance, formerly WECA (Wireless Ethernet Compatibility Alliance), the group which ensures compatibility between hardware devices that use the standard. Today, due to misuse of the terms (and for marketing purposes), the name of the standard is often confused with the name of the certification. A Wi-Fi network, in reality, is a network that complies with the standard. With Wi-Fi, it is possible to create high-speed wireless local area networks, provided that the computer to be connected 325 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

2 is not too far from the access point. In practice, Wi-Fi can be used to provide high-speed connections (11 Mbps or greater) to laptop computers, desktop computers, personal digital assistants (PDAs) and any other devices located within a radius of several dozen meters indoors (in general 20m-50m away) or within several hundred meters outdoors. Wi-Fi providers are starting to blanket areas that have a high concentration of users (like train stations, airports, and hotels) with wireless networks. These access areas are called "hot spots" Range and data flow Figure. 1: Wi-Fi Architecture The a, b and g standards, called "physical standards" are amendments to the standard and offer different modes of operation, which lets them reach different data transfer speeds depending on their range [3] The a Standard Frequency Speed Range WiFi a (802.11a) 5 GHz 54 Mbit/s 10 m WiFi a (802.11a) 2.4 GHz 11 Mbit/s 100 m WiFi G (802.11b) 2.4 GHz 54 Mbit/s 100 m Table 1: The Wi-Fi Standards The standard has a maximum theoretical data flow of 54 Mbps, five times that of b, but at a range of only about thirty metres. The a standard relies on a technology called OFDM (Orthogonal Frequency Division Multiplexing). It broadcasts in the 5 GHz frequency range and uses 8 non-overlapping channels. Because of this, a devices are incompatible with b devices. However, there are devices that incorporate both a and b chips, called "dual band" devices[3]. Hypothetical speed Range (indoors) 54 Mbits/s 10 m 48 Mbits/s 17 m 36 Mbits/s 25 m 24 Mbits/s 30 m 12 Mbits/s 50 m 6 Mbits/s 70 m Table 2: The a Standards 326 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

3 2.1.4 The b The b standard allows for a maximum data transfer speed of 11 Mbps, at a range of about 100 m indoors and up to 200 metres outdoors (or even beyond that, with directional antennas)[3] The g Hypothetical speed Range (indoors) Range (outdoors) 11 Mbits/s 50 m 200 m 5.5 mbits/s 75 m 300 m 2 Mbits/s 100 m 500 m 1 Mbit/s 150 m 500 m Table 3: The b Standards The g standard allows for a maximum data transfer speed of 54 Mbps at ranges comparable to those of the b standard. What's more, as the g standard uses the 2.4GHz frequency range with OFDM coding, this standard is compatible with b devices, with the exception of some older devices [3] Benefits of using Wi-Fi Hypothetical speed Range (indoors) Range (outdoors) 54 Mbits/s 27 m 75 m 48 Mbits/s 29 m 100 m 36 Mbits/s 30 m 120 m 24 Mbits/s 42 m 140 m 18 Mbits/s 55 m 180 m 12 Mbits/s 64 m 250 m 9 Mbits/s 75 m 350 m 6 Mbits/s 90 m 400 m Table 4: The g Standards The benefits of Wi-Fi are to enable wireless access to deliver voice, data, and video streams with no cables attached. The benefits of Wi-Fi include: Enable staff to carry portable Wi-Fi handsets giving them the ability to take calls anywhere, anytime Using Wi-Fi enables PDA s and Laptops to deliver quick and easy access to information Eliminate cellular usage charges Eliminate cabling and wiring for PC s Eliminate switches, adapters, plugs, pins, and connectors Wi-Fi helps in increasing revenues in Businesses like Hotels and other public places by creating hotspots to attract customers. 2.2 WiMAX Introduction WiMAX is one of the hottest broadband wireless technologies around today. WiMAX systems are expected to deliver broadband access services to residential and enterprise customers in an economical way. Loosely, WiMax is a standardized wireless version of Ethernet intended primarily as an alternative to wire technologies (such as Cable Modems, DSL and T1/E1 links) to provide broadband access to customer premises. More strictly, WiMAX is an industry trade organization formed by leading communications, component and equipment companies to promote and 327 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

4 certify compatibility and interoperability of broadband wireless access equipment that conforms to the IEEE and ETSI HIPERMAN standards. WiMAX would operate similar to WiFi but at higher speeds over greater distances and for a greater number of users. WiMAX has the ability to provide service even in areas that are difficult for wired infrastructure to reach and the ability to overcome the physical limitations of traditional wired infrastructure. WiMAX was formed in April 2001, in anticipation of the publication of the original GHz IEEE specifications. WiMAX is to as the WiFi Alliance is to [4]. WiMAX is: Acronym for Worldwide Interoperability for Microwave Access. Based on Wireless MAN technology. A wireless technology optimized for the delivery of IP centric services over a wide area. A scaleable wireless platform for constructing alternative and complementary broadband networks. A certification that denotes interoperability of equipment built to the IEEE or compatible standard. The IEEE Working Group develops standards that address two types of usage models: (i) A fixed usage model (IEEE ). (ii) A portable usage model (IEEE e). [4] IEEEE Standards The IEEE e-2005 amendment to the IEEE Std Air Interface Standard which added Scalable- Orthogonal Frequency Division Multiple Access (S-OFDMA) and many other features for support of mobility has provided the basis for WiMAX System Release 1. Further specification enhancements for Release 1 were provided with IEEE Std e The first WiMAX System Release 1 deployments took place in Estimates by the WiMAX Forum indicate that as of the end of 2009, WiMAX service providers have covered more than 600 million people with over 500 deployments in over 140 telecommunications markets worldwide. In December 2006 the IEEE launched an effort to further evolve the IEEE Wireless MANOFDMA specification. This amendment, known as m, is designed to meet or exceed the requirements of IMT-Advanced (the 4th generation of cellular systems). With a number of stringent requirements for backwards compatibilit y, the m amendment will provide the basis for WiMAX System Release 2 and provide existing WiMAX operators a graceful migration path to gain performance enhancements and add new services. The IEEE m task group has more than 300 participating individuals from approximately 100 organizations from two dozen countries. As was the case for e-2005, m is designed to support frequencies in all licensed IMT bands below 6 GHz and include TDD and FDD duplexing schemes as well as half-duplex FDD (H-FDD) terminal operation to ensure applicability to the wide range of worldwide spectrum assignments. Completion of the IEEE m specification is expected in the 3rd quarter of 2010 with ratification soon thereafter. Initial availability of WiMAX System Release 2 products based on m is anticipated in the 2012 timeframe. This paper provides an overview of the enhancements incorporated in the IEEE m amendment and subsequently, WiMAX System Release 2. For the purposes of discussion the planned performance enhancements can be grouped into the following six categories: [5] Increased Coverage and Spectral Efficiency Increased Capacity for Data and VoIP Lower Latency and QoS Enhancements Interworking with other Wireless Networks Power Conservation Other Advanced Features and Supported Services Lower Latency and QoS Enhancements Interworking with other Wireless Networks Power Conservation Other Advanced Features and Supported Services [5] 328 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

5 2.2.2 Standards Associated With WiMAX Figure. 2: WiMAX Architecture The IEEE , the Air Interface for Fixed Broadband Wireless Access Systems, also known as the IEEE WirelessMAN air interface, is an emerging suite of standards for fixed, portable and mobile BWA in MAN. These standards are issued by IEEE work group that originally covered the wireless local loop (WLL) technologies in the GHz radio spectrum, which were later extended through amendment projects to include both licensed and unlicensed spectra from 2 to 11 GHz. The WiMAX umbrella currently includes and e utilizes OFDM to serve multiple users in a time division fashion in a sort of a round -robin technique, but done extremely quickly so that users have the perception that they are always transmitting/receiving e utilizes OFDMA and can serve multiple users simultaneously by allocating sets of tones to each user. Figure 3: Standards Associated With WiMAX 329 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

6 Notes: WAN: Wide area network MAN: Metropolitan area network LAN: Local area network PAN: Personal area network IJRREST Following is the chart of various IEEE Standards related to WiMAX Types of WiMAX Technology (802.16) Table 5: IEEE Specifications The Wimax family of standards (802.16) concentrate on two types of usage models a fixed wimax usage model and a mobile wimax usage model. The basic element that differentiates these systems is the ground speed at which the systems are designed to manage. Based on mobility, wireless access systems are designed to operate on the move without any disruption of service; wireless access can be divided into three classes; stationary, pedestrian and vehicular. A. Fixed Wimax Broadband service and consumer usage of fixed Wimax access is expected to reflect that of fixed wire-line service, with many of the standards-based requirements being confined to the air interface. Because communications takes place via wireless links from wimax Customer Premise Equipment (wimax CPE) to a remote Non Line-of-sight (NLOS) wimax base station, requirements for link security are greater than those needed for a wireless service. The security mechanisms within the IEEE standards are sufficient for fixed wimax access service. Another challenge for the fixed wiimax access air interface is the need to set up high performance radio links capable of data rates comparable to wired broadband service, using equipment that can be self-installed indoors by users, as is the case for Digital Subscriber Line (DSL) and cable modems. IEEE standards provide advanced physical (PHY) layer techniques to achieve link margins capable of supporting high throughput in NLOS environments [6]. B. Mobile Wimax The a extension, refined in January 2003, uses a lower frequency of 2 to 11 GHz, enabling NLOS connections. The latest e task group is capitalizing on the new capabilities this provides by working on developing a specification to enable mobile Wimax clients. These clients will be able to hand off between Wimax base stations, enabling users to roam between service areas [6]. C. Wimax backhaul Wimax backhaul is actually a connection system from the Access Point (AP) back to the provider and to the connection from the provider to the network. A wimax backhaul can set out any technology and media provided; it connects the system to the backbone. In most of the Wimax deployments circumstances, it is also possible to connect several wimax 330 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

7 base stations with one another by use of high speed wimax backhaul microware links. This would also allow for roaming by a Wimax subscriber from one wimax base station coverage area to another, similar to roaming enabled by cellular phone companies [6] Benefits of WiMAX A. Coverage and Range: The maximum cell radius for a WiFi network is an eighth to a quarter of a mile. The range of WiMAX is 3 to 5 miles from the antenna, depending on the frequency and topography. This wider coverage for WiMAX means that more customers can be connected to the network with at a lower cost. With a lower investment in infrastructure, it is now possible to profitably serve rural areas with lower population densities, as well as economically depressed areas in cities with lower broadband adoption rates. WiMAX is designed to serve entire communities, a Metropolitan Area Network (MAN), as municipal Wi-Fi, which uses unlicensed spectrum, failed to do. For rural areas, the current range of WiMAX networks is comparable to mobile phones. B. Non-Line-of-Sight (NLOS) Service: Many 3G mobile phones and radio devices require a line-of-sight (LOS) connection between the access point and user s modem. Mobile WiMAX standard features a 256 carrier OFDM technology which significantly enhances the NLOS capabilities of the radio. This allows the operator to support more customers per cell site due to better signal penetration. C. Higher Data Rates: WiMax is able to achieve download speeds ranging up to 6 Megabits per second for fixed residential service and up to 4 Mbps for mobile users. Residential WiMAX is able to achieve a higher data rate because it has a longer antenna. In the future, WiMAX data rates will be able to be increased by decreasing cell size in more populus areas, thereby giving users multiple access points. D. Interoperability Advantage: WiMAX represents a shift in strategy for designing and operating wireless broadband data networks. WiMAX compliant devices from different device manufacturers will be able to operate on the same network. This increases the viability and decreases the risk with deploying wireless broadband networks. E. Improved Quality of Service (QoS): The improved Quality of Service built into the WiMAX technology platform will enable carriers to offer features designed for use by commercial enterprises. WiMAX will also be a pipeline for media-rich applications for personal use, such as gaming or multicast video (once IPv6 is introduced). F. Lower Consumer Premises Equipment (CPE) Cost: The cost of WiMAX modems and compliant devices will fall as multiple equipment vend ors compete with one another in introducing their products. A proprietary system, such as LTE, does not take advantage of economies of scale, as much as an open standards technology platforms. [7] 3. DIFFERENCE BETWEEN WIMAX AND WI-FI The basic difference between Wimax technology and Wifi technology are cost, speed, distance and so on. Wimax coverage is about 30 miles and Wifi coverage is very limited to some small area. Wimax network just as an ISP without any cable because Wimax singnal used to get access to internet to your home or business, while Wifi will be used inside in your local area network (LAN) for access to the internet. The Wimax architecture is design to make possible metropolitan area networking (MAN). The base station of Wimax capable to provide access to business and hundred of homes, While Wifi is providing only local area networking (LAN). The deployments of Wimax and Wifi network are same both ISP would have their T3 access. The line of sight antennas used to connect tower in Wimax technology. The tower shared out the non line of sight to MAN. The line of sight antennas for Wimax network operate at 60 MHz frequency while the tower having non - lines of sight operate on a range just like the WiFi. 331 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

8 The base or tower station of Wimax will beam a signal to receiver of Wimax. Similarly Wifi access point transport signal to the receiving device. Wimax network providing QoS (Quality of Service) therefore a large number of people get access to tower at the same time. The built in algorithm automatically transfer the user to other tower or cell of Wimax station. Unlike Wifi user have to sort of fight to stay on connected with a specified access point. The most significant issue of Wimax and WiFi difference is pricing because Wimax is a high cost network, while Wifi is a low cost network therefore mostly people adopt WiFi network due to less expenditure and avoid Wimax due to expensive installations. WiMax will not put out of place WiFi in the home because WiFi is much better in speed and technolo gy. With the passage of time new improvement brings a new variant in Wimax offering high speed but if a client exists away from tower or base station speed could decreases. Wimax offer high speed internet as a broadband access which transfer data, v oice, video at very high speed. While WiFi offer short range of data transfer because WiFi can connect only in specified areas so only file sharing may possible. Wimax design for long range distance in licensed spectrum or unlicensed spectrum. Wimax support point to point or point to multipoint connection. Multiple standard of wimax such as e, b for mobile connectivity from fixed location. While WiFi offer quality services to fixed Ethernet where packets are precedence on their tag. Hotspots of WiFi are usually backhauled over ADSL in small business, café etc therefore to get access is normally highly challenging. The uploading speed of wifi as compared to Wimax also very low rate among internet and router. Wimax network execute a connection oriented MAC while Wifi runs on the CSMA/CA protocol, which is wireless and strife based. Parameters WiMAX (802.16a) Wi-Fi ( b) Wi-Fi (802.11a/g) Primary Application Broadband wireless access Wireless LAN Wireless LAN Frequency Band Licensed/Unlicensed 2 to 11 Ghz 2.4 GHz ISM 2.4 GHz ISM(g) 5 GHz-U(a) Channel Bandwidth Adjustable 1.25MHz to 20 25MHz 20 MHz MHz Duplex Full Half Half Radio Technology OFDM DSSS QFDM Bandwidth 5bps/Hz 0.44 bps/hz 2.7 bps/hz Efficiency Modulation BPSK,QPSK,16.64,256QAM QPSK BPSK,QPSK,16,64QAM FEC Convolutional, reed solemon None Convolutional codes Mobility Mobile WiMAX(802.16e) In deployment In deployment Access Protocol Grant Request CSMA/CA CSMA/CA 4. FUTURE DEVELOPMENT Table 6: Difference b/w WiMAX and Wi-Fi The IEEE m standard is the core technology for the proposed WiMAX Release 2, which enables more efficient, faster, and more converged data communications. The IEEE m standard has been submitted to the ITU for IMT- Advanced standardization. IEEE m is one of the major candidates for IMT-Advanced technologies by ITU. Among many enhancements, IEEE m systems can provide four times faster data speed than the current WiMAX Release 1 based on IEEE e technology. WiMAX Release 2 will provide strong backward compatibility with Release 1 solutions. It will allow current WiMAX operators to migrate their Release 1 solutions to Release 2 by upgrading channel cards or software of their systems. Also, the subscribers who use currently available WiMAX devices can communicate with new WiMAX Release 2 systems without difficulty. It is anticipated that in a practical deployment, using 4X2 MIMO in the urban micro cell scenario with only a single 20-MHz TDD channel available system wide, the m system can support both 120 Mbit/s downlink and 60 Mbit/s uplink per site simultaneously. 332 P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2

9 5. CONCLUS ION This study explored the performance details of WiMAX and Wi-Fi access technology. WiMAX and Wi-Fi integration convenient and affordable broadband connectivity that brings new deployment models for service all providers, as well as new usage models for subscribers. It aims was also to study whether WiMAX applications could provide better network performance compare to Wi-Fi. At the same time to explore the performance and QoS of both WiMAX and Wi-Fi wireless access. The ability to be connected to the Internet and to have access to real-time information in more places is of high value to both business professionals and consumers services. 6. REFERENCES [1] [2] [3] [4] [5] [6] [7] P a g e IJRREST h t t p : / / i j r r e s t. o r g / i s s u e s /? p a g e _ i d = 1 2