jueves, 22 de julio de 2010

The LTE threat


While WiMax has been slowly ramping up, LTE has been playing catch-up. Long-Term Evolution, like WiMax, is a 4G wireless data transfer technology that promises similar ranges and performance. Unlike WiMax, which is based on an IEEE standard, LTE is driven by a loose collection of telecommunications companies that support the existing Global System for Mobile communications (GSM) standard.

GSM vendors control approximately 80% of the worldwide mobile market today, according to ABI Research. These carriers see LTE, an outgrowth of GSM that is designed to be backward-compatible with it, as the obvious next step for their networks. "It's the logical upgrade path for both GSM and UMTS (Universal Mobile Telecommunications System), and for broadband data services like HSPA (High Speed Packet Access)," said Mathias. Even Verizon Wireless, a CDMA (Code Division Multiple Access) carrier, is lining up behind LTE, he noted.

"The cellular carriers are on an evolutionary path to LTE, [but] it is difficult to figure out when LTE will be a significant competitor and have material impact on WiMax adoption," Peter Stanforth, chief technology officer and co-founder of Spectrum Bridge Inc., an online market for wireless spectrum, said in an e-mail. While WiMax is finally gaining critical mass, LTE is still taking its first steps. AT&T, for instance, expects to make LTE service commercially available in 2011. Verizon has a faster timetable, saying it plans to have networks in 25 to 30 cities in 2010.

"It is true several carriers have said that they are going to start the LTE rollout soon, but when will it have enough coverage to be significant?" Stanforth asked. "If it's just a few base stations in a few major cities in order to say 'We have deployed LTE,' will consumers know or care?"

In an ABI research report from the second quarter of 2009, senior analyst Nadine Manjaro wrote, "Vendors will only begin shipping base station equipment in significant quantities in 2010, followed by full commercial launches in 2011." While "many operators have been talking about re-use of existing equipment," ABI expects that "most ... base stations will have completely new baseband and RF components, because operators will generally try to keep the new LTE networks separate from their legacy networks," she wrote.



ABI predicts that there will be at best 34 million LTE users at the end of 2011, with perhaps twice as many WiMax users. And Adlane Fellah, an analyst at telecommunications research firm Maravedis Inc., even speculated that carriers who intend to deploy LTE in a few years might turn to WiMax in the short term to take pressure off their 3G networks.

Although LTE is lagging behind WiMax today and will likely do so for the next few years, it's far from certain that WiMax will win this fight in the long run. "To LTE's credit, WiMax's head start has lessened, and LTE has the support of most major mobile operators," said Daryl Schoolar, principal analyst for wireless infrastructure at research firm Current Analysis Inc., in an e-mail exchange.

"WiMax, on the other hand, has in most cases been the technology of choice for new market entrants -- Tier 2 and Tier 3 operators," Schoolar continued. "This gives LTE the advantage, as its operators often have deeper pockets and established relationships with the end user. Both attributes are needed to get a new network up and running."

Unless WiMax deployment rates speed up, LTE will become the dominant 4G data network by 2015, predicts ABI Research principal analyst Phillip Solis. Farpoint Group's Mathias concurs. "LTE will have the footprint, services, and carrier and vendor support to make almost everyone happy, especially when coupled with Wi-Fi, which it will often be," he said. "WiMax isn't going away, but its opportunities for growth will be severely limited, and I don't think that there's much that can be done about that either from a business or a technology perspective."

Looking ahead

Stanforth sees a role for WiMax as a public service, recalling the failure of many municipal Wi-Fi efforts, such as those in San Francisco, Chicago, St. Louis and Springfield, Ill., and speculating that WiMax might be better suited to the task. "Muni Wi-Fi flopped primarily because of both the lousy coverage of Wi-Fi and the cost to even get that -- it took 60-plus Wi-Fi [access points] per square mile to implement using a typical mesh architecture, whereas a single WiMax AP will probably cover well over a square mile. The economics of 'Muni WiMax' might make sense," he said.

Lori Sylvia, executive vice president of marketing at Red Bend Software Inc., which makes WiMax device-management software, thinks WiMax service delivery and infrastructure costs will need to decrease in order for WiMax to compete with DSL and cable. When all providers, no matter what technology they use, can provide multiple Mbit/sec. speeds, "then the buying criteria becomes like any other Internet service: coverage and cost," Sylvia said via e-mail.

Brough Turner, an independent wireless analyst and blogger, isn't optimistic. In an e-mail, Turner wrote, "The problem is WiMax products can never achieve the volumes associated with the GSM family of technologies (GSM, UMTS, HSPA, LTE). As a result, WiMax will always cost more to deploy, and WiMax handsets will be more expensive than comparable GSM family handsets. It doesn't matter if WiMax is 'better' than LTE or not, or that WiMax is ahead today. The installed base of GSM family technologies generates very high volumes for GSM family products. As those products migrate to LTE, LTE product volumes will drive costs well below WiMax costs."

It's not necessarily an either/or proposition, however. "In my opinion, LTE and WiMax will co-exist, as they are actually targeting different markets," said Schoolar of Current Analysis. "LTE for the most part is an extension of the current mobile ecosystem. It will primarily be used to do what we are doing today with 3G, but better. WiMax's primary market, however, will be more about fixed and portable services. As much as I hate to say it, WiMax really will be Wi-Fi on steroids. While WiMax's head start over LTE has diminished, I don't think it matters as much as people think, as the two technologies are running a separate race."


José Galviz 17.206.921

http://www.computerworld.com/s/article/9137908/WiMax_in_2010_Too_little_too_late_?taxonomyId=15&pageNumber=3

WiMax lucha por mantenerse como opción frente a LTE




Hace unos años parecía que WiMax iba a ser una de las tecnologías que se usarían cada vez más, algunas pequeñas ciudades lo comenzaron a usar pero con el paso de los años se ha ido viendo como no terminaba de desplegarse a un ritmo adecuado y todo hace indicar que va a perder la batalla frente a LTE.

LTE son las siglas de Long Term Evolution y se trata de una evolución de la norma 3GPP y es el principal candidato para hacerse con la denominación 4G. De hecho se trata de la evolución más natural frente a WiMAX que entre otras cosas permitiría a las operadoras tener una mejor adaptación de las antenas para comenzar a usar esta tecnología. De cara a los consumidores ofrece velocidades de hasta 100 Mbps de bajada en un solo canal y en general, un una mejor estabilidad de la señal en determinadas situaciones.

WiMax Forum no quiere tirar la tolla tan rápido y han acordado una serie de mejoras para hacer frente a LTE, entre las que se encuentran mejoras para reducir las interferencias en la señal, una velocidad más alta, duplicación de potencias, un 70% más de eficiencia espectral entre otras.

Pero a pesar de esto el futuro es muy negro para WiMax y parece difícil frenar la adopción de LTE anunciada por diversas operadoras, entre ellas Clearwire, el mayor operador de WiMax del mundo, quienes han mostrado estar dispuestos a utilizar LTE en el futuro.

Desde WiMax Forum afirman que una buena solución sería que las operadoras utilizarán las dos tecnologías, lo cual podría darse durante un tiempo pero finalmente sería una de las dos la que terminaría usándose más y poco a poco conquistandoel mercado. Pero realmente que las operadoras decidan usar ambas tecnologías no parece demasiado viable, teniendo en cuenta que una adopción de LTE sería más barata lo cual podría permitirles rentabilizar su adopción de una forma más rápida.


José Galviz 17.206.921

http://alt1040.com/2010/06/wimax-lucha-por-mantenerse-como-opcion-frente-a-lte

The promise of WiMax


Clearwire and partners like Intel, Comcast, Time Warner Cable and Ciscowant to change the last networking mile in the same way that Wi-Fi changed the last 100 feet of networking: by complementing or possibly replacing the existing technologies.

WiMax can cover up to 31 square miles instead of the few hundred square feet per access point provided by the more familiar 802.11g and 802.11n Wi-Fi technologies. In theory, WiMax can also deliver more than 75Mbit/sec. data-transfer speeds. In practice, it doesn't have either that range or that speed. But with real-world speeds of up to 9Mbit/sec., it's about as fast as today's standard 802.11g (though not as fast as 802.11n), and it offers far greater range than any Wi-Fi technology.

Arthur Giftakis, vice president of engineering at Towerstream Corp., a national WiMax provider for businesses, believes WiMax will deliver "high-speed mobile services that consumers and business users alike are demanding more and more," such as the ability to watch sports highlights on a laptop on the train or download apps on a handheld device. "WiMax will enable you to do those things faster than previous technologies," he said in an e-mail interview.

WiMax incorporates quality of service technologies for prioritizing network traffic, and that is particularly important for voice-over-IP and video applications, noted Joel Payne, vice president of engineering and operations atSparkplug Inc., a national Internet service provider serving the business market. In contrast, Wi-Fi access points can be overwhelmed by multiple clients demanding simultaneous access. "The WiMax protocol will be important for applications that require a lot of data to be transmitted on time, and to decrease packet loss and latency," said Payne via e-mail.

Jesse Jones, owner of Matanuska Wireless, a data communications company in Palmer, Alaska, agreed, citing Internet Protocol television as a technology that can greatly benefit from improved quality of service. "IPTV via WiMax is one of the most exciting developments," Jones said in an e-mail interview. However, he added, "there is no word yet" on when the first working IPTV via WiMax models will be available.

How fast, how far, how much?

Just how high-speed is WiMax? The honest answer is "it depends."

"Speed and coverage area depend on several factors, such as frequency, terrain and tower height," Jones explained. "Any amateur radio operator or electrical engineer can tell you that propagation characteristics vary significantly based on frequency." In other words, a deployment on 700 MHz will have a different coverage area than one based on 2.3 GHz or 3.65 GHz.

Further, "the flat, open fields of Kansas will see different coverage on 3.65 GHz than my neighborhood nestled at the base of three mountain ranges in Alaska," he continued. A base station mounted 40 feet high on a tower will reach far fewer subscribers than if it was mounted 80 feet high. And the amount of throughput users see on a wireless connection is directly related to the signal quality, Jones said. "You really can't make general statements related to speed and coverage because not every deployment is the same."

Clearwire reports that its WiMax users are seeing average speeds of 4Mbit/sec. to 6Mbit/sec., with bursts exceeding 15Mbit/sec. -- about the same throughput that DSL services provide. To get that level of performance, you can expect to pay about as much as you currently do for DSL.

Although WiMax offers no huge speed advantage over today's technologies, pricing may be a selling point. Towerstream's Giftakis said, "I can confirm that our business customers will be paying less than market T1 prices to get WiMax. On the consumer side, Clearwire is offering service from $10 for a day to $50 for a month. I don't expect this will drastically change in the near term.

WiMax, Wi-Fi or both?

To access WiMax, you're going to have a wide variety of hardware choices, including notebooks, netbooks, handhelds and mobile Internet devices with built-in WiMax radios, according to Julie Coppernoll, director of marketing forWiMax at Intel Corp. "Numerous embedded WiMax laptops based on Intel Centrino 2 processor technology are now available," she said via e-mail. In addition, USB modems will bring WiMax into your home or office, replacing your wired Internet connection.

But WiMax won't necessarily replace Wi-Fi. WiMax/Wi-Fi translators, such as Cradlepoint Inc.'s Clear Spot router, can create a local Wi-Fi network from a WiMax signal. That Cradlepoint device, which is available now, allows any existing, off-the-shelf Wi-Fi device to connect to a Clearwire WiMax network, said Coppernoll. "The Clear Spot creates a personal Wi-Fi hot spot that travels with consumers anywhere they happen to be within Clearwire's mobile WiMax service area," she said. Using it, people can avoid local Wi-Fi hot spot fees -- and, as WiMax rollouts continue, they might be able to pick up WiMax service in areas where they can't find a Wi-Fi hot spot.

Other companies are also bridging the gap between WiMax's 802.16 and Wi-Fi's 802.11 protocols. Cisco Systems Inc., for instance, plans to introduce devices with that capability under its Linksys brand within the next six months.

Wi-Fi Alliance executive director Edgar Figueroa also sees WiMax and Wi-Fi working hand in glove rather than the newer technology replacing the older. "While WiMax provides excellent range, Wi-Fi's performance profile and power consumption traits make it the right networking technology for the local area," he said in an e-mail interview. "As we're seeing today on the cellular side, WiMax providers will also look to Wi-Fi as an alternative connection to migrate users from scarce licensed spectrum -- and users will gravitate to Wi-Fi for its affordability."


José Galviz 17.206.921

http://www.computerworld.com/s/article/9137908/WiMax_in_2010_Too_little_too_late_?taxonomyId=15&pageNumber=1

¿Cuáles son las diferencias entre WiFi, WiMAX y WiBro?

Si bien casi todos los tipos de redes inalámbricas puede parecer confuso, hay algunas cosas sencillas para tener en cuenta sobre la diferencia entre los estándares inalámbricos conocido como WiFi, WiMAX y WiBro. Cada uno de ellos es similar en que cada uno proporciona una manera de conectarse a una red inalámbrica para la comunicación de estación de trabajo o acceso a Internet. Sin embargo, cada tecnología puede ser visto como una mejora de la anterior también.

WiFi que se conoce como el estándar 802. 11. Hay un número de sub-series como la 802. 11 (a) (b) o (g). Las generaciones posteriores de esta tecnología han aumentado la velocidad y alcance. Su uso más común es proporcionar Internet inalámbrico para los usuarios de computadoras portátiles. Sin embargo, aún con los avances en WiFi, hay una serie de limitaciones.

WiFi tiene algunas desventajas inherentes. Por ejemplo, mientras Wi-Fi pueden trabajar bien en lugares localizados, los routers utilizados para las conexiones no tienen una tremenda cantidad de rango. En la mayoría de los casos, de 300 pies (aproximadamente 100 metros) es el límite de la tecnología. Por lo tanto, para las redes inalámbricas más grandes y conectividad, se necesita otro estándar. Estas limitaciones son una de las razones redes inalámbricas municipales han fracasado.

WiMAX es un estándar diferente conocido como el 802. 16. Sólo permite a los usuarios tantos en la norma y luego cortar cualquier usuarios adicionales tratando de utilizar la conexión. Esto es diferente que el WiFi, que permitirá, en teoría, un número ilimitado de usuarios, que a su vez atascar el sistema. A pesar de ello, la mayor diferencia es el rango. Para los que no línea de visión, el rango es de 25 millas cuadradas (65 kilometros cuadrados). Para la línea de visión entre el punto de transmisión y la antena de recepción, la gama de saltos de hasta 2. 800 millas cuadradas (9. 300 kilómetros cuadrados).

WiBro es muy similar a WiMAX. Las velocidades de transmisión son las mismas, pero la principal diferencia es que WiBro puede rastrear un receptor que se mueve de un lugar a otro. También puede ser llamado WiMAX móvil. Sin embargo, no es realmente móvil en el sentido de que puede ser utilizado de manera efectiva, mientras que el receptor se mueve a gran velocidad. Por el contrario, simplemente significa que el receptor puede moverse de un lugar a otro y la experiencia sin degradación en el servicio, siempre y cuando el receptor se mantiene dentro del rango. WiMAX no ofrece esto porque necesita una antena fija para recibir una señal.

Una cosa a tener en cuenta acerca de WiBro es que es mucho todavía en el proceso de desarrollo. , Ya que mejora, puede llegar un momento en que los receptores serán capaces de mantener las conexiones incluso cuando viaja a altas velocidades. En esos casos, se puede llamar de una norma completamente diferente con un nombre completamente diferente.

José Galviz 17.206.921

miércoles, 21 de julio de 2010

WiBro, el WiMax en movimiento


WiBro son las siglas en inglés de Wireless Broadband, una tecnología deInternet de banda Ancha que está siendo desarrollada por empresas de Telecomunicación Coreanas. Aunque algunos la confunden o la asocian con WiMax, esta tecnología es una alternativa más dentro de la comunicación inalámbrica.

Los canales de comunicación de WiBro tienen un ancho de banda 8,75 MHz, e implementa el estándar IEEE 802.16e (Mobile Wimax). Su objetivo principal no es proporcionar una increible velocidad de conexión, sino más bien proporcionar una conexión fiable y estable con una velocidadadecuada para dispositivos móviles en movimiento. Esto quiere decir que un dispositivo WiBro podría conectarse a Internet sin problema aunque esté moviéndose hasta 250 km por hora.

Aunque esto es la teoría, en la práctica también hay muy buenas perspectivas ya que las compañías Coreanas SK Telecom y Korea Telecomempezaron a ofrecer el servicio el año pasado, eso sí con una velocidad de entre 30 a 50 Mbit/s a hasta 120 km/h. A principios de abril de 2007 existíacobertura WiBro en el metro de Seul


José Galviz 17.206.921

http://tecnyo.com/wibro-el-wimax-en-movimiento/