XMAX Technology

XMAX TECHNOLOGYDRK Institute of Science & Technology Page 1 XMAX TECHNOLOGY CHAPTER-1 INTRODUCTION DRK Institute of Science & Technology Page 2 . Using cognitive (i. The operator is facing a choice of acquiring more licensed spectrum (if any is available) or losing customers due to demand for advanced services.1Current Situation: Wireless operators today are facing a dilemma. smart) radios and advanced system and signal processing capabilities. Finally. DRK Institute of Science & Technology Page 3 . tablets and laptops today. chat and other applications are required for customers that are very mobile. and instantly move into vacant channels while avoiding occupied ones. Support for voice. The xG system is designed to support these devices through a physical or WiFi connection. However. xG Technology is developing an affordable mobile voice and data cellular system that operates in free unlicensed bands using what is known as cognitive radio technology.XMAX TECHNOLOGY 1. the operator is using scarce expensive licensed spectrum that is overburdened with delivering core voice services. the xG system is all-IP protocol based so that it can utilize COTS (commercial off-the-shelf) infrastructure components for network connectivity. standard applications and established management interfaces.1. data.1Cognitive Radio: Cognitive radio (CR) is a form of wireless communication in which a transceiver can intelligently detect which communication channels are in use and which are not. the xG system makes unlicensed spectrum communications as reliable as licensed band communications. Customers are demanding more and more data applications to be delivered on the go. This optimizes the use of available radio-frequency (RF) spectrum while minimizing interference to other users. xG Technology has a solution to this dilemma of overwhelming demand for advanced applications versus lack of spectrum. Another advantage of xG’s cognitive radio approach is the reduction of the RF engineering the operator needs to deploy and maintain the system. 1.e. A third benefit of this system is the ability to reuse all the engineering going into smartphones. This is made possible by effectively mitigating the interference in the congested and chaotic unlicensed bands. location awareness. utilities. The company has commercialized some of these technologies to create xMax.2 About xG Technology: xG Technology is a leading developer of innovative and disruptive communications technologies for wireless networks. Its extensive patented intellectual property portfolio covers a broad range of applications including cognitive radio networks. real time video.1 Logo of xG 1. it was designed with the following requirements in mind:    Leverages COTS end user devices including 3G and 4G smartphones. the world’s first carrier-class cognitive radio network. xMax enables the delivery of mobile services in both licensed and unlicensed bands. Using field-proven cognitive radio technology.3 xMax Mobile Voice and Data Overview: xMax is a mobile voice and data solution from xG Technology that has been designed to address the issues raised above and more. as well as self-Radio Frequency (RF) planning and selforganizing. chat and other apps. Dynamic Spectrum Access (DSA) and advanced interference mitigation to increase operational and deployment flexibility. tablets and netbooks without requiring licensed commercial frequencies. In particular. 5g Full cognitive networking capabilities including dynamic access and optimization of available spectrum resources. Fig:1. A single end-to-end IP network architecture supporting mobile voice. Page 4  DRK Institute of Science & Technology . xMax offers unique capabilities to enterprises.XMAX TECHNOLOGY 1. wideband data. management and operational costs while simplifying the delivery of fixed and mobile services. xMax’s standards-based IP architecture minimizes network deployment. government agencies and others who require advanced wireless communications to support business operations and mission critical applications. XMAX TECHNOLOGY CHAPTER-2 xMax NETWORK COMPONENTS DRK Institute of Science & Technology Page 5 . XMAX TECHNOLOGY Fig:2 xMax cellular Network 2. The following are the major components of the system: xMod xAp xMSC x Monitor/x Drive DRK Institute of Science & Technology Page 6 .xMax Cellular Architecture: The xMax mobile cellular solution leverages a standard cellular architecture – with some notable enhancements. 5Mbps to the connected end user device(s) under real world conditions Fig:2.1 xMod 2.2 xAP DRK Institute of Science & Technology Page 7 .XMAX TECHNOLOGY 2.2 xAP: The xAP acts as a compact. Each xAP can deliver up to 14 Mbps of total user bandwidth to its associated xMods. Fig:2.1 xMod: The xMod is a small battery or vehicle-powered radio that bridges the COTS end user device to the wideband transport layer of the xMax system. high-performance base station and wirelessly connects to the xMod using the xMax cognitive networking waveform. Devices may be physically tethered or connected via secure WiFi links to the xMod. xAPs may be deployed individually or in clusters of up to 9 xAPs to increase total throughput. The xMod can deliver up to 3. as well as mobile network throughput and coverage optimization.4 xMonitor/Drive DRK Institute of Science & Technology Page 8 . Fig:2.3 xMSC 2. It performsrouting and security functions. as well as proprietary mobile VoIP optimization and compression. The xMSC is typically connected to the worldwide Internet and one or more VoIP soft switches.4 xMonitor/xDrive: These software tools provide integrated and comprehensive network and element management for the xMax network. Fig:2.XMAX TECHNOLOGY 2.3 xMSC: The xMSC acts as both a base station controller and aggregation point for the connected xAPs. XMAX TECHNOLOGY CHAPTER-3 WORKING OF XMAX TECHNOLOGY DRK Institute of Science & Technology Page 9 . The xMax xAP supports both Ethernet and Fibre interfaces. Another benefit of xMax’s cognitive technology is that the network has the ability to self-configure and self-organize. Voice is transported as mobile-optimized Voice over IP (VoIP). Since this is a shared spectrum resource. This interface. COTS routers and switches are used as network components. This is planned to be further enhanced to support full meshing capabilities in future xMax product releases. Standard SIP signalling supports integrated COTS voice switches and gateways. Both the xAP and xMod devices are frequency agile and have several built-in capabilities to mitigate interference by first employing advanced signal/spatial processing as well as dynamically switching channels to avoid overwhelming interference or jamming. The air interface between the xMod and xAP is an advanced Physical Layer (PHY) featuring OFDM modulation and MIMO transmit and receive. combined with other xG innovations. unlicensed spectrum.3 Advanced cognitive sensing.1 End-to-end IP architecture and shared spectrum optimization: All the components of the xMax system are IP based. or an external (cloudbased) switch/gateway service may be utilized.825 GHz band for license free operation. signal and multi-spatial processing: Real time RF sensing and dynamic spectrum access are the cornerstones of xMax radio technology. 3.5.XMAX TECHNOLOGY 3. xMax’s Dynamic Spectrum Access technology is frequency agnostic and can be re-tuned to operate in TV white spaces. including Dynamic Spectrum Access to provide reliable operation in unlicensed but interference prone spectrum. implementing interference immunity and spectral efficiency was paramount for commercial applications. The commercial xMax system (slated for release in H1 2012) utilizes the 902-928 MHz and the 5. enabling the entire system to operate as a data packet network – but with full voice calling features. was optimized to provide licensed quality service in free. 3. DRK Institute of Science & Technology Page 10 . Using these freely available bands allows the xMax system to scan over 125 channels (in release 3) for interference-free operation.2 Cognitive operation including DSA and interference mitigation: xMax employs advanced cognitive radio and networking techniques.725. unlicensed or licensed commercial bands. PHY layer and software radio design: The xMax PHY layer is designed with a proprietary 2x4 (two transmitters. which allow longer cyclic prefixes. This MIMO system enables longer range. WiMAX. WiFi and other solutions.1 Dynamic channel selection 3. QAM16 and QAM64 modes that allow the system to dynamically self-configure for the optimal combination of range.XMAX TECHNOLOGY Fig:3. in addition to minimizing power consumption for extended battery life and remote operation. This combination of capabilities enables increased performance under dynamic conditions.4 Advanced antenna. This results in low overhead and high usable throughput (as a percentage of total over the air bandwidth). The xMax PHY supports adaptive modulation with BPSK. DRK Institute of Science & Technology Page 11 . four receivers per link) multiple input multiple output (MIMO) antenna and radio configuration. throughput and interference rejection. QPSK. higher throughput and is a key enabler of the xMax interference mitigation technology. The xMax system utilizes proprietary long OFDM symbols. The system uses orthogonal frequency division modulation (OFDM) which is found in other state-of-the-art wireless systems such as LTE. This is critical for maximizing reliability as well as increasing the utilization of scarce spectrum resources. Since the technique is primarily implemented within the receiver chain.XMAX TECHNOLOGY 3. xMax can operate effectively under higher interference and jamming levels than competing solutions. This technique significantly increases the system capacity of an xMax network.2Spatial processing to Jamming and Interference DRK Institute of Science & Technology Page 12 .5 Interference tolerance. the RF environment is not made noisier as would be the case for mitigation techniques that rely on raising the transmitter power to overcome the interferer. frequency reuse and high link reliability: By applying cognitive capabilities to enhance active interference mitigation. By enabling xMax to tolerate high levels of interference before requiring the radios to switch channels. more “gray spectrum” (spectrum containing interference or jamming) can be used in place of white spectrum (clean and interference-free spectrum). Fig:3. This capability increases the network’s total throughput and capacity greatly – without consuming additional scarce spectrum resources. XMAX TECHNOLOGY CHAPTER-4 Wi-Fi DRK Institute of Science & Technology Page 13 . 2. with the router receiving information from the Internet. translating it into a radio signal and sending it to the computer's wireless adapter.4 GHz or 5 GHz. They can transmit and receive radio waves. and some cities are trying to use the technology to provide free or lowcost Intrnet access to residents.XMAX TECHNOLOGY 4. The higher frequency allows the signal to carry more data. In fact.1 WiFi Network 4.1 Wi-Fi: Wireless networking.11 networking. This frequency is considerably higher than the frequencies used for cell phones. and they can convert 1s and 0s into radio waves and convert the radio waves back into 1s and 0s. just like cell phones. walkie-talkies and televisions. But WiFi radios have a few notable differences from other radios: They transmit at frequencies of 2. also called WiFi or 802. cell phones and other devices.  DRK Institute of Science & Technology Page 14 . communication across a wireless network is a lot like two-way radio communication. televisions and radios do.2 What Is Wi-Fi? A wireless network uses radio waves. is used to connect the computers at home. A wireless router receives the signal and decodes it. The radios used for WiFi communication are very similar to the radios used for walkietalkies. The process also works in reverse. wired Ethernet connection. Here's what happens: 1. The router sends the information to the Internet using a physical. Fig:4. A computer's wireless adapter translates data into a radio signal and transmits it using an antenna. The organization that owns the Wi-Fi (wireless fidelity) term specifically defines Wi-Fi as any "wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers' (IEEE) 802. 802.it can handle up to 54 megabits of data per second. For a while.11b. 802. This greatly reduces interference.11 networking standards. however.4 GHz like 802. like wide area networks (WANs) inside vehicles or technology that lets you move from one wireless network to another seamlessly. Frequency hopping helps reduce interference and lets multiple devices use the same wireless connection simultaneously.11b is the slowest and least expensive standard.4 GHz frequency band of the radio spectrum.2 Logo of Wi-Fi DRK Institute of Science & Technology Page 15 . WiFi radios can transmit on any of three frequency bands.11g theoretically moves 54 megabits of data per second. 4. reportedly can achieve speeds as high as 140 megabits per second. This standard significantly improves speed and range. although 802.11g is faster because it uses the same OFDM coding as 802." Fig:4.11n. 802.11b transmits in the 2. users can experience interference or lose their connections.the Institute of Electrical and Electronics Engineers (IEEE) plans to formally ratify 802.11n by the end of 2009. a more efficient coding technique that splits that radio signal into several sub-signals before they reach a receiver.11 standards focus on specific applications of wireless networks. they can "frequency hop" rapidly between the different bands. if the router fails or if too many people try to use high-bandwidth applications at the same time. it only achieves real-world speeds of about 24 megabits of data per second because of network congestion. several devices can use one router to connect to the Internet. its cost made it popular. but now it's becoming less common as faster standards become less expensive. which come in several flavors: 802.11g transmits at 2. It can handle up to 11 megabits of data per second. Or. 802.11a. It also uses orthogonal frequencydivision multiplexing (OFDM). For instance. virtually invisible and fairly reliable. and it uses complementary code keying (CCK) modulation to improve speeds. Other 802.3 The name Wi-Fi: The name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections.11 standards. however. 802.XMAX TECHNOLOGY    They use 802. As long as they all have wireless adapters.11a transmits at 5 GHz and can move up to 54 megabits of data per second. 802. but it's a lot faster -. The standard is currently in draft form -. This connection is convenient.11n is the newest standard that is widely available. This is not to say there can't be any more big developments in digital radio communications. and in other ways but not from breakthroughs in modulation. xG Technology is the one claiming to have a new and vastly more power-efficient modulation method so it is entirely up to them to prove it. and some of these schemes already come very close to the theoretical limits. The xMax demo may impress those who haven't done the calculations and are unaware of how little power it actually takes to transmit digital data over a benign line-ofsight path.91 dBm. Broadcast stations use such powerful transmitters because they cannot assume line of sight paths. xG would have lowered the signal level and eliminated the margin to make its demo seem more impressive. dialup modems reached their theoretical limits years ago. but Internet access speeds continue to rise thanks to cable modems. By way of analogy.1 dB less power for WiFi compared to xMax at the same speed. because there won't be any more. The Ruckus Wireless 802. But one can reasonably presume that if this were the case. cooperative ad-hoc networking. But the same demonstrated performance could have been easily achieved with just about any conventional digital modulation scheme.11g transceiver specifies a receiver sensitivity of only -96 dBm at 6 Mb/s. improved interference mitigation. and DSL. fibre deployments. the received signal power at the xMax receiver was -120. better adaptivity to changing or hostile radio link conditions. or 7.4 Comparison between xMax and Wi-Fi: As calculated above. reflections and interference throughout their entire service areas. It is possible that the xMax demo operated with link margin. including an off-the-shelf WiFi transceiver. Opportunities still abound in frequency reuse. That's 5 dB less power for almost twice the data rate (6 Mb/s Vs 3. In any event. fading. improved spectrum sharing.91 dBW or -90. DRK Institute of Science & Technology Page 16 . far from it! But they will not come as fundamental modulation breakthroughs from xG Technologies or anyone else. improvements in RF hardware that will let us make better use of the underutilized higher frequency bands. Note that this comparison does not require any estimates. meaning that it could have worked on a weaker signal than the one used. radio networking.XMAX TECHNOLOGY 4. multiple-out (MIMO) antenna arrays. This is because receiver sensitivity figures combine the effects of system noise and demodulator/decoder Eb/N0. the basis of modern cellular phones. while the Eb/N0 calculation above required that we estimate the noise temperature of the receiving system. multiple-in. large margins are required to reliably overcome obstacles.7 Mb/s). 5 xMax and Wi-Fi differences: Table:4.1 Differences between Wi-Fi and xMax technology DRK Institute of Science & Technology Page 17 .XMAX TECHNOLOGY 4. XMAX TECHNOLOGY CHAPTER-5 ADVANTAGES . DISADVANTAGES & APPLICATIONS OF XMAX TECHNOLOGY DRK Institute of Science & Technology Page 18 . net books and other end –user devices. Substantially lower capital requirements for materially more sophisticated product offering.off mechanism.    DRK Institute of Science & Technology Page 19 . Path to 4G performance with a revolutionary battery solution for user device.real time video. chat and other apps over a single integrated network. The xMax system’s cognitive networking capability allows it to dynamically access and optimize available spectrum resources. Network capacity managed through software-defined radio system. xMax’s cognitive networking technology is frequency agnostic and can be adapted to a wide array of TV spaces. Header compression. Exclusive service territories. The coverage and capacity of the network can be tailored to the market and business model at hand and can be rapidly reconfigured to support new or expanded applications. scalable mobile wide band solution that is capable of supporting a wide range of smart phones. No spectrum license costs. 5. Zero latency network configuration. xMax’s end-to-end IP network architecture supports mobile voice.2 APPLICATIONS:   The completely new mobile VoIP system that is similar to most popular VoIP service providers like skype.tablets.XMAX TECHNOLOGY 5. Soft hand.widwband. unlike typically 3G and 4G networks that require separate voice and data network equipment and transport layers. unlicensed frequency bands. xMax cognitive radio cellular system represents a complete.1 Advantages:           Quality of service (QoS) to support long ranges mobile VoIP. Deterministic latency on wireless links for voice packets. while also enabling it to optimize its own RF plan. nomadic. There is also an issue with quality. US-based xG Technology has addressed these problems with its xMax system. rather than licensed spectrum and an all-IP architecture that is less expensive to operate than traditional networks.3 Disadvantages:  VoIP technology is great at saving its users money. IPaXIom gives businesses. There still seems to be issues to address. and VoIP calls are blocked on some networks by cellular companies concerned that they are missing out on revenues. it can also deliver mobile wireless broadband connectivity across vast open and congested areas. over many kilometres.      FUTURESCOPE: The XMAX™ technology can provide fixed. portable solution and with OFDMA at the heart of the technology. With the XMAX™ Customer Premises Equipment. as the phone eventually overheated. The XMAX™ comes with its own NMS for comprehensive and user friendly day-to-day management and support function. Although the test was limited in its scope. enterprise and the end customer get more options for broadband connectivity at lower cost. DRK Institute of Science & Technology Page 20 . but it seems that mobile VoIP could not be too far away. but it does have some disadvantages – you have to be connected to a computer to use it. which has been specifically designed for mobile VoIP. as cellular networks are not designed for Internet voice traffic. The network uses available free spectrum. he used a phone connected to a laptop while being driven around Fort Lauderdale and reported that the voice quality was fine.XMAX TECHNOLOGY 5. revised 29 June 2007 Prof. Prospective investors should be very wary. certainly nothing that would call into question the fundamental principles of communication theory that have been firmly established for six decades. References:        www. And a reading of xG's published claims and patents belie a surprising lack of awareness of these principles. Ben Friedlander's blog on xMax and other wireless fantasies.000. DRK Institute of Science & Technology Page 21 . no spectacular results have been demonstrated.com A review of Bobier's TriState Integer Cycle Modulation.000 times less power than WiFi. added 17 June 2007.xgtechnology. added 4 June 2007 comments on Prof. added 16 May 2007 comments on MiCOM lab test of xMax. Despite xG's implications to the contrary.XMAX TECHNOLOGY Conclusion: From my analysis it seems that xG's xMax technology is nothing special. Stu Schwartz's evaluation of xMax added 6 June 2007 an analysis of xG's claims that xMax requires 3. added 21 June 2007 Comments on Patent Application 20040196910 from an engineer who wishes to remain anonymous. XMAX TECHNOLOGY DRK Institute of Science & Technology Page 22 .