Read - VIA and Everex demonstrate Cloudbook MAX at CTIA
Read - VIA VX800 Series Chipset
Friday, April 11, 2008
SPRINT'S XOHM WIMAX SUPPORTED LAPTOP
Read - VIA and Everex demonstrate Cloudbook MAX at CTIA
Read - VIA VX800 Series Chipset
NOKIA N810 WIMAX INTERNET TABLET IS READY?
Nokia has showed their WiMax future N810 WiMax enabled tablet in CTIA 2008 conference, looks like it is getting official WiMax enabled ready for market of Nokia. Their main target is start to sell it in the most deployed WiMax network country USA for this summer. Beyond that, you'll notice the familiar 4.13-inch touchscreen, slide-out QWERTY keyboard and even a built-in webcam for video calls, Mozilla-powered browser, integrated GPS / media player, 2GB of internal memory and a microSD expansion slot. Heck, Nokia even touts this thing's ability to "access the Internet over WiFi or via conventional cellular data networks by pairing to a compatible mobile phone via Bluetooth technology." Also announced today is the freshly updated OS2008, which includes an enhanced e-mail client, support for Chinese character rendering in the browser and RSS feeds and "Seamless Software Update functionality" to boot. Needless to say, said OS will come standard on the currently unpriced Nokia N810 WiMAX Edition -- which is scheduled to land wherever WiMAX connectivity is available -- but existing N810 / N800 owners will also get the OS upgrade free of charge in Q2.
SIEMENS GIGASET SERIES RELEASING NEW EXPRESS CARD
Siemens putting the new card of their GIGASET WIMAX series products. The Gigaset SE68 WiMAX is based on the IEEE 802.16-2005 standard and complies with Wave 2 specifications (including MIMO A / B), supports beamforming and has actually been demonstrated as functional way over in Singapore. With a network in place, users can expect mobile broadband speeds of up to 20Mbps, and while no price is given, you can just circle the entire summer of 2008 in anticipation of its arrival.
MOBILE WIMAX DEPLOYMENT ALTERNATIVES
Traditionally, cellular deployments were based solely on achieving ubiquitous coverage with little consideration for capacity requirements. Since the only services offered were voice and the market was uncertain, this was a very reasonable approach. Moreover, the voice service offering is a low data rate application enabling traditional cellular networks to achieve wide outdoor and indoor coverage with a low data rate network (~10-15 kbps bandwidth depending on type of vocoder). As the customer base grew and more services offered, additional base stations were deployed and/or channels added to existing base stations to meet the growing capacity requirements. With Mobile WiMAX, however, operators will want to offer a wide range of broadband services with Quality-of-Service (QoS) support. To meet customer expectations for these types of services it will be necessary to predetermine capacity requirements and deploy accordingly at the outset. Careful deployment planning in anticipation of growing customer demands will ensure a quality user experience when the network is at its busiest.
Determining Capacity Requirements
Arriving at an accurate estimate of capacity requirements for new broadband services is not a simple exercise. One must anticipate how users will make use of the new services being offered and how often users will be actively engaged with the network. Data density, expressed as Mbps per km^2, is a convenient metric for describing capacity requirements. Determining the required data density for a specific demographic region is a multi-step process.The expected market penetration, or take-up rate, at maturity is dependent on a number of factors including the competitive situation and the services offered that distinguish one service provider from another. The service provider’s penetration may also vary within the metropolitan area since urban and dense urban residents will often have other broadband access alternatives from which to choose as compared to residents in suburban and rural areas.
Base Station Deployment Alternatives
Mobile WiMAX base station equipment will be available from many different vendors and, although all will be WiMAX compliant and meet performance and interoperability requirements, a great many different configurations will be available from which service providers can choose. The availability and timing of optional features also adds to the equipment variability. Additionally, there are different frequency bands that can be considered and varied amounts of spectrum availability within these bands. The spectrum choices will, in many cases, affect the frequency reuse factor and the channel bandwidths that can be employed in the access network.WiMAX solutions with beamforming will generally be architected quite differently from
SIMO and MIMO solutions. A typical SIMO or MIMO configuration will have power amplifiers mounted at the base of the tower to facilitate cooling and maintenance. The amplifiers in this case would have to be sized to compensate for cable losses, which can range from 2 to 4 dB depending on tower height and frequency. Beamforming solutions require good phase and amplitude control between transmitting elements and will often be architected with their power amplifiers integrated with the antenna elements in a tower-mounted array. The larger size and weight of these structures will also require more robust mounting. There is additional signal processing requirements for beamforming solutions with Adaptive Beamforming being the most computational intensive.
The selection of channel bandwidth and duplexing method can also have an economic impact on the varied WiMAX deployment alternatives. In addition the desired “worse case” UL rate will affect the UL link budget and therefore, impact the range and coverage of the base station.
Conventional cellular deployments used cell frequency reuse factors as high as seven (7) to mitigate intercellular co-channel interference (CCI). These deployments assured a minimal spatial separation of 5:1 between the interfering signal and the desired signal but required seven times as much spectrum. With technologies such as CDMA, introduced with 3G, and OFDMA, introduced with WiMAX, more aggressive reuse schemes can be employed to improve overall spectrum efficiency.
Number of Base Stations
The key metric for a quantified comparison will be the number of WiMAX base stations required to meet both capacity and coverage requirements in the varied demographic regions. The WiMAX base station is a key network element in connecting the core network to the enduser in that it determines the coverage of the network and defines the end-user experience. If too few base stations are deployed the coverage will not be ubiquitous and the end-user may experience drop outs or periods of poor performance due to weak signal levels as he moves throughout the coverage area. And since the base station investment will tend to be a dominant contributor to the total end-to-end network costs, deploying too many base stations can result in unnecessary start-up costs for the operator leading to a weaker business case.
Summing up
In the long term, the higher performance base stations with wideband channels provide a potentially more cost-effective deployment solution as measured by the number of required base stations. One might conclude that it would be worth waiting for antenna technologies such as beamforming and beamforming + MIMO and possibly even 20 MHz channels, before deploying a Mobile WiMAX network. This however, is not the case. In the early years , deployment can begin with range-limited base stations using (1x2) SIMO or (2x2) MIMO base station configurations to get ubiquitous coverage over the entire metropolitan area. These base stations can then be upgraded in the following years with beamforming and beamforming + MIMO as necessary to meet the capacity requirements in anticipation of a growing customer base. In most metropolitan area deployments this will only be necessary in the dense urban and urban areas.
Wednesday, March 19, 2008
WHEN BROADBAND WIRELESS AND SATELLITE SERVICES COLLIDE
The C-band frequency is used worldwide by fixed satellite services (FSS) operators to eliver TV transmissions, distancelearning, telemedicine, disaster recovery, meteorological and earth observation services, and also by certain military services. Today, there are approximately 160 geostationary satellites operating in the C-band frequency worldwide. In addition, two out of every three commercial satellites under construction will utilize C-band. The deployment of broadband wireless access (BWA) services, including WiMax, has been gaining momentum in several countries. BWA equipment, slated to operate within the 3.4-3.7 GHz ranges of the FSS extended C-band frequency, has been demonstrated to severely interfere with satellite communications operating within the C-band. Early Indications With several national administrations having designated portions of the C-band for terrestrial wireless applications, including BWA and future mobile services, massive interruptions of satellite services, radar and microwave links has occurred in those regions. Interference has also been reported in other parts of the world, including Australia, Bolivia, Fiji, Hong Kong, Indonesia, Pakistan, Kazakhstan, and Sub-Saharan Africa. Compatibility testing in areas where WiMax services are being implemented has clearly indicated the potential for significant threat to satellite services operating in Cband. A BWA field trial in Hong Kong, for example, inadvertently knocked off the TV-signal feeds to an estimated 300,000 households throughout Asia.Taking on Spectrum Sharing The satellite industry mobilized effectively to lobby the ITU and governing organizations against sharing the 3.4-3.7 GHz ranges of the FSS extended C-band frequency spectrum. Several prominent organizations, including APSCC, the Asia- Pacific Broadcasting Union, Asia- Pacific Telecommunity, and the Global VSAT Forum (GVF),
When Broadband Wireless and Satellite Services Collide SATELLITE TRENDS The well organized “no change” lobbying campaign orchestrated by the satellite industry resulted in a landlark decision during WRC'07 to preserve the C-band srpectrum for interference- free delivery of satellite communications. Robert Ames President and CEO SUIRG, Inc. 34 APSCC Quarterly Newsletter ted position papers to the ITU while major satellite operators vigorously engaged the ITU and other regulatory administrations on this issue. In preparation for the November ITU World Radiocommunication Conference (WRC) 2007, the Satellite Users Interference Reduction Group (SUIRG), in collaboration with GVF, the U.S. Navy and several other industry organizations conducted a field test to assess whether WiMax systems would cause severe interference to satellite systems and to measure the xtent of such interference. The test was conducted in two phases in RF-quiet areas to ensure no external signals contaminated the test results.
Testing was performed using a Prodelin-provided fixed satellite service antenna, Vertex/RSI-provided LNA and a WiMax unit. The NSS 806 satellite, located at 319.5°E, was used for both phases of the test with the baseline video signal sent from a TT&C earth station in Manassas, Virginia. The FSS antenna was aligned to receive a video program channel at 3,515 MHz. Phase 1: The testing was conducted in Punta Gorda, Florida where the FSS antenna stayed at a fixed location and the WiMax transmitter, positioned at a slightly elevated level of about 3 meters, was moved to a variety of locations. The FSS receive C/N (carrier/noise) was set to a nominal 10 dB. At the receiver down-converter (D/C) output, the Bit Error Rate (BER) and digital power of the carrier were measured to establish a baseline. The WiMax transmitter and omni-directional antenna were fixed to a vehicle and set to transmit at various frequencies and power outputs. Field testers adjusted the WiMax transmitter to various frequencies and various output power levels. C/N, I/N (interference /noise), BER, and video quality results were then measured at the FSS antenna along with spectrum plots for each phase of the test. Phase 1 testing was designed to simulate a subscriber unit operating within the vicinity of an FSS antenna system. Phase 2: The second test phase was held in the Southern Maryland and Northern Virginia areas. The WiMax antenna and base station were mounted on a water tower at an elevation of 50 meters, with a down tilt angle of 8 vertical (typical of cellular tower antennas). The FSS antenna was moved to several locations transmitting at differing angles from the WiMax antenna. Before the start of Phase 2 testing the C/N, I/N, BER, and video quality results were measured at the FSS antenna along with spectrum plots for each phase of the test. These results acted as a baseline for the Phase 2 testing.
The FSS antenna was moved varying distances and placed at differing angles relative to the fixed WiMax transmitter, with the same measurements made at each location. Field testers adjusted the WiMax transmitter to various frequencies and various output power levels, and measured the same parameters as in Phase 1. The purpose of Phase 2 testing was to provide field data relative to the distance required to meet the maximum long-term WiMax generated IN of -10 dB specified for an exclusion zone where WiMax systems could not be installed. Results the WiMax Forum provides for an interference to- noise ratio of -10 dB, whereby the WiMax signal should be at least 10 dB below the carrier noise floor. However, the findings of the field test indicate significant interference where the lowest I/N level measured at the test FSS antenna was found to be 7 dB above the noise floor. In addition, the WiMax base station and antenna used during Phase 2 have a maximum Eq uivalent Isotropic Radiated Power (EIRP) of 34 dBm. ITU studies and regulating bodies have used 44 dBm for the protection of FSS earth stations. Extrapolating the test data for defining the distance required between FSS and WiMax systems indicate an exclusion zone of 280 km, which would restrict WiMax systems to extremely remote locations. “The results identified significant levels of interference generated by the WiMax system,” said Robert Ames, President of SUIRG. “The importance of C-band services dictates urgency when dealing with this potential threat. We hope that the results of our field test will make a difference in the decision-making process for re-allocating this critical frequency for terrestrial wireless services.” The well organized “no change” lobbying campaign orchestrated by the satellite industry resulted in a landmark decision during the ITU World Radiocommunication Conference (WRC) 2007, held 22 October- 1 November in Geneva, to preserve the C-band spectrum for interference- free delivery of satellite communications. The resulting decision restricts International Mobile Telecommunications (IMT), including WiMax, from any part of the satellite C-band (3.4-4.2 GHz). The ITU table of allocations remains unchanged, with the limited number of countries in favor of change identified in an opt-in footnote. By taking this approach, the world’s regulators participating in the WRC have made it clear that the C-band is off limits for IMT and have preserved the precious spectrum for satellite communications. The WRC further restricted IMT, specifying adherence to stringent requirements for the protection of existing and future satellite services in the C-band, including transborder protection. For example, in Region 2 (the Americas and the Caribbean), there is no identification for IMT, just an upgrade through a footnote, in 14 countries of the mobile service allocation in 3.4-3.5 GHz. In Region 3, only eight countries inserted their name to the footnote identifying IMT. Only in Region 1 was there broader support from countries to be included in the footnote identifying IMT for national use.
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