Introduction
With the emergence of advanced technology in the telecommunication industry in the last decade, the demand for access to the internet through mobile devices has increased. This has propelled the wireless telecommunication industry to work hard in developing air interfaces that would provide a platform for broadband services with high frequencies. In that case, this would boost generally the system capacity, improve spectral efficiency as well as reduce latency. To achieve this, the key players WiMAX and the LTE have come up with mobile voice provision, data, and video services. The models applied use protocols and architectures that are internet friendly. These are the two leading standards and they are seen as the only ones that will be able to provide mobile network standards for the next generation. The paper aims to give a comparison between the WiMAX and the LTE in full detail by way of discussing the different aspects involved.
LTE
The LTE is a concept that was to be completed in 2009 with the radio air interface being in the development process. The LTE will use the all IP Core Network that is developed to use the 3GPP standards. The WiMAX concept is being applied in the development of the LTE where different aspects have been adopted. For instance it will be using the LTE is already adopting the features and technology that has been used by Mobile WiMAX (Gray, 2009). This will bring similarities that will ensure that the two standards operate from the same platform Some of the adopted features are the OFDMA in DL with 64QAMAll IP e2e Network, Channel BWs up to 20 MHz, TDD and FDD profiles, Flexible Access Network, Advanced Antenna Technologies, UL: Single-Carrier FDMA (SC-FDMA), (64QAM optional (Gray, 2009 )
WiMax vs. LTE
The WiMax and LTE are designed to use “low cost deployment and service models through internet-friendly architectures and protocols” (Bhandare, 2008). Pazhyannur (2009) adds that the LTE and the WiMAX aim at lowering the costs of the infrastructure used. The traditional mobile networks use the TDM and combination of the packet infrastructure that is partial, but with LTE and the WiMAX, they have simplified the network standards to the application of all- IP networks. This network is able to transport data and control messages. The two networks have employed a flattered architecture that aims at eliminating the “centralized base station controller for Radio Network Controller (RNC) in favor of distributing the functionality to Base Stations and Access Gateways” (Bhandare, 2008). The two networks operate with flexible spectrum. In the recent past the networks that existed operated using a fixed-width spectrum, but these two allow scalability with the range width of 125MHZ to 20MHZ. The WiMAX uses a variable spectrum width of 125MHZ to 10MHZ while LTE uses a width of 3MHZ to 20MHZ.
According to Bhandare (2008) the LTE and the WiMAX have taken the advantage of the radio channel spatial diversity. They have applied the MAT (Multiple Antenna Techniques) that can provide wide signal coverage as well as improve the performance of the system. Pazhyannur (2009) adds that this would increase the efficiency of the networks that allow the usage of high modulation schemes and smart antenna technologies (MIMO). The LTE and the WiMAX use saleable OFDM on their downlink, although the uplink of both differs. The LTE uses a Single Carrier FDMA while the WiMAX uses an OFDM uplink (Pazhyannur, 2009). They also use Multiple Input Multiple Output (MIMO) that is looped. Other than that, the two use the closed-loop for their MIMO in the Downlink spectrum. The Uplink and the Downlink usage aim to improve the peak data rates so that wireless videos can be easily relayed.
The system-level functionality of the LTE and the WiMAX is quite similar. Through the eNodeB and the BS the networks are able to handle the traffic to the subscriber device and from the same. According to Pazhyannur (2009) this is done by functioning like the Radio Resource Management based on the control plane. It is able to authenticate and set up connections, allocate resources as well as perform functions that include transmission of data packets. Also they both use IP tunnel that routes user plane traffic to the gateway access (Pazhyannur, 2009). The Core Network Systems and the RAN of the LTE and the WiMAX are based on IP application. This makes them have no defined air interfaces so they directly eliminate the need to pass via core network system. The LTE and the WiMAX operate under the BS interface. According to Pazhyannur (2009) the two have optional interfaces that route the traffic and directly deliver them to the BS. The WiMAX uses the R8 while the LTE applies the X2 interface. These improve the latency in the BS handovers, minimize the control as well as traverse the user place traffic to access gateways (Bhandera 2008).
There are multiple mobility forms in both the LTE and the WiMAX. This is defined through the relay of the BS that is connected in totally different access gateways. The MIMO in both the LTE and the WiMAX has options like the Space-Time Block Coding (STBC) and the Spatial Multiplexing (SM). For example, the LTE is able to allow 4 times 4 MIMO while the WiMAX allows 2 times 2 MIMO. The Duplexing Mode of the WiMAX is defined as the TDD while the LTE is defined as the FDD and the TDD (Pazhyannur (2009). The FDD applies paired spectrum where one belongs to the Uplink while the other is attached to the downlink. The TDD uses the contiguous spectrum that has the benefit of reciprocating the nature of the channel. This according to Pazhyannur (2009) allows the beamforming that gives room for stabilization of multipath in wide-area coverage for MIMO deployments. The FDD and the TDD systems are synchronized to ensure that there is no interference between the Uplink and the Downlink. This prevents any bursts in the cross-section of different BS.
Differences between LTE and WiMax
There are differences that exist between the LTE and the WiMAX. Based on the argument that they both use the MIMO and the OFDMA, the interface efficiency is totally different. The LTE has better efficiency than the WiMAX but there is an expectation that the WiMAX would be better off after the modifications are carried out. The deployment of the two networks seems to be different also. For instance, operations that use the FDD spectrum can apply the LTE and supplement the operators that are already using the GSM (3G). On the other hand, WiMAX can be the right choice for the operators that are using or willing to adopt the TDD spectrum (Pazhyannur, 2009). It can also be applied to operators who have frequency range of between 2.5GHZ and 3.5GHZ and the emerging cellular operators.
Another difference that arises is the implementation of the networks. The LTE and the WiMAX operate using the same technology of the air interface, nonetheless the implementation is different. For example, the LTE uses the FDD and TDD which is different from the WiMAX. Also the spectrum is released differently where one releases at a rate of 1msec while the other releases at 5msec duration frame (Pazhyannur, 2009). For the SubCarrier Frequency the LTE uses a frequency of 15KHZ while the WiMAX has a subcarrier frequency of 10KHZ. The deployment of the two is also different. The LTE cellular operators believe in the usage of the already existing frequency of the WiMAX. The Uplink transmission between the LTE and the WiMAX is also different. For instance, WiMAX uses OFDMA in both Uplink and the Downlink (Bhandare, 2008). On the other hand, the LTE applies the OFDMA on its uplink operations whole on its downlink Single Carrier Frequency Division Multiple Access (SC-FDMA). The reason why the LTE uses the SC-FDMA is that is used to reduce the Peak to Average Power Ratio (PAPR). The protocols applied in the WiMAX and the LTE are all different in the gateways passage and the BS (Bhandare, 2008).
The services and service models of the LTE and the WiMAX are different in their operations. For instance, the LTE has few operators who may be willing to use the fixed services (Pazhyannur, 2009). The LTE business model operates to impact the economies of scale to decrease the technology flexibility. On the other hand the WiMAX has a large broadband width that can support the download and upload fast with low latency for its video, voice and multimedia services (Bhandare, 2008). The WiMAX is prepared to provide a Global roaming support as well as support fixed, portable, nomadic and mobile usage (Pazhyannur, 2009).
According to Bajwa (2009) the LTE is promising with the provision of high speed and two-way data transmission. The voice calls will be provided through the VoIP and can handle video more through the satellite and WiFi. This will succeed the 3G technologies and provide the 4G technologies. The WiMAX is already in the market but the LTE is in its development stages, and the LTE is seen as the revolution that would overthrow the WiMAX (Bajwa, 2009). The radius cell coverage using the LTE is 5Km for the LTE while the WiMAX has a range of 20.7 km and 8.4 km for its two different broadband. The speed mobility of the LTE is 350km/h for cell that is handover supported while the WiMAX goes up to 120km/h for the optimized hard handovers supported (Bhandare, 2008). On the other hand LTE uses specific layers for security in the control plane and user plane security. The security is supported by the UEA1, UIA1, UEA2, and the UIA2 (Bhandare, 2008). On the other hand, the WiMAX uses Advanced Encryption Standards (AES) that supports encryptions. This provides stronger security than the LTE and enhances the stronger coding schemes used. The Extensible Authentication Protocol (EAP) used in the WiMAX allows the application of many utilities like passwords, smartcards as well as usernames applications (Pazhyannur, 2009).
Conclusion
The LTE and the WiMAX are the next technology networks that will change the wireless telecommunication industry. The two networks share broad similarities in their architecture and the air interface as well as in the system level. For instance, the two use the looped MIMO that allows the use of multiple antennas that reduces latency as well as enable efficient deployment. The LTE and the WiMAX are supported by the TDD and the FDD that have the scalable spectrum of between 125MHZ to 10MHZ. This allows peal performances that have the same modulation and coding. They both allow multiple mobility data that is relayed to different gateway routes via the BS. The WiMAX and the LTE have the same functionality where it is possible to relay data packets to and from using the subscriber device. The two apply the MAT that is able to provide wide signal coverage as well as improve the performance of the system. This is prospected to increase the efficiency of the networks that allow the usage of high modulation schemes and smart antenna technologies (MIMO). Also the two use the closed-loop for their MIMO in the Downlink spectrum. The Uplink and the Downlink usage aim to improve the peak data rates so that wireless videos can be easily relayed. The WiMAX allows fast uploads and downloads than the LTE. The application of the EAP allows the use of usernames and passwords in the WiMAX improving the security of the cellular. LTE is able to transmit its networks in a radius of 5km while the WiMAX allows ratio of 8.4km to 20.7km in the respective broad bands. The speed mobility of the two is different with the LTE having a speed of 350km/h and the WiMAX at a speed of 120km/h.
Reference List
Bajwa, A. (2009). LTE vs WiMAX: The 4G wireless war. Web.
Bhandare, T. (2008). Comparison of LTE and WiMAX. Web.
Gray, D (2009). Comparing mobile WiMAX with HSPA+, LTE, and Meeting the goals of IMT-Advanced. Web.
Pazhyannur, R.S. (2009). Comparison of LTE and WiMAX. Web.