Mobile Virtual Network Operator (MVNO)

In recent news, Comcast became the first cable MVNO (Mobile Virtual Network Operator) in the U.S. to offer high-speed WiMax services announcing “Comcast High-Speed 2go”.

http://www.wimax.com/commentary/blog/blog-2009/june-2009/comcast-launches-first-wimax-market-0630

MVNO (Mobile Virtual Network Operator): an organization that buys minutes and services wholesale from an existing carrier (or carriers) and resells them under its own brand. Under GSM, for example, it may issue its own SIM card. A MVNO is basically a reseller. It does not have radio frequency (spectrum) nor does it have its own communications plant. It usually has its own billing system, however. A company that does have its own frequency allocation is simply known as a Mobile Network Operator (MNO). Any of the wireless technologies used on the existing network can be used by the MVNO (e.g. CDMA, GSM, UMTS, etc)

Examples of MVNO’s:

- Boost Mobile
- Mobile PCS
- Virgin Mobile

MVNO’s are typically autonomous entities that works independently of the MNO, giving it the ability to set its own pricing structure, subject to the rates of the network operator. Some MVNO’s run their own Billing and Customer Care solutions known as BSS (Business Support Systems). However, many use a MVNE (Mobile Virtual Network operator Enabler) which we will discuss on Monday.

WiMax

Today we will talk about WiMax. In the next WotD we will differentiate between 4G and WiMax as these 2 terms seem to be synonymous when coming up in conversation and it’s important to know the difference between the two (as well as how they are related).

WiMax: Worldwide Interoperability for Microwave Access, is a Broadband Wireless Access (BWA) solution that is based on standards recommendations from both the IEEE 802.16 working group and the ETSI (European Telecommunications Standards Institute). WiMax is promoted by the WiMax Forum, a special interest group comprising members of the manufacturing, carrier and service provider communities. The IEEE established the 802.16 working group to standardize Local Multipoint Distribution Services (LMDS) and Multichannel Multipoint Distribution Services (MMDS).

There are 2 types of WiMax:

1) Fixed WiMax (no support for mobility)
2) Mobile WiMax

Various uses of WiMax include:

· Connecting Wi-Fi hotspots to the Internet.
· Providing a wireless alternative to cable and DSL for "last mile" broadband access.
· Providing data and telecommunications services.
· Providing a source of Internet connectivity as part of a business continuity plan. That is, if a business has both a fixed and a wireless Internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage.
· Providing portable connectivity.
· WiMax applications include private campus networks, T-1 and Fractional T-1 business service, rural or developing areas where cabled broadband service is not available, Wi-Fi hotspot backhaul and disaster recovery (as demonstrated during Hurricane Katrina).

Sources: http://en.wikipedia.org/wiki/WiMAX;
Newton’s Telecom Dictionary, 22nd Edition; 2006

Companies and WiMax:
Companies have been investigating the use of WiMax to target the “last mile” broadband access for rural communities where broadband access was previously economically unviable. This would help open up new potential wireless markets and help compete with cable/DSL offerings for Internet service. Other significant movements in the wireless industry include:

- In 2006, Sprint announced its intent to invest $5 Billion into WiMax
- In 2007, WiMax base stations quadrupled from 5,000 to 20,000 globally
- In 2008, a new company, Clearwire, (now with Sprint owning a majority share of the company at 51%) was formed by the aggregation of 120Mhz of spectrum owned by various companies in the hopes to benefit from combined service offerings and network resources (with the intent that cable companies are able to provide content using the network as a MVNO: Mobile Virtual Network Operator)
- As of June 2009, there were roughly 475 deployments of WiMax in 140 countries reaching nearly 430 million people worldwide (numbers include planned, in-process and commercialized networks)
- Looking beyond 2009, Verizon Wireless (along with MetroPCS Wireless and U.S. Cellular) will be the lead network operator touting the LTE standard for 4G (competing alongside Sprint’s WiMax offering)

Source: http://www.itbusinessedge.com/cm/community/features/articles/blog/lte-versus-wimax-moves-from-theoretical-to-real/?cs=34099

MIMO (Multiple Input/Multiple Output) **4G Technology**

*Another technology/technique involved in 4G communications

MIMO (Multiple Input/Multiple Output): MIMO is a wireless technology that employs multiple intelligent input and output radio antennas to improve transmission speed and quality over longer distances than otherwise possible. The technique involves Space Division Multiplexing (SDM), with arrays of multiple spatially separated transmit and receive antennas. The idea is to push 802.11 (also known as Wi-Fi) WLAN (Wireless Local Area Network) transmission rates from around 20 Mbps to at least 100 Mbps and perhaps as high as 540 Mbps. MIMO also will extend 802.11 distances from 100 meters to as much as 200 meters. MIMO is the basis for the developing IEEE 802.11n standard and promotes spectral efficiency during 4G communications. MIMO is typically combined with OFDM (Orthogonoal Frequency-Division Multiplexing) to achieve an even greater level of spectral efficiency.

OFDM (Orthogonal Frequency Division Multiplexing) **4G technology**

In the next few WotD’s we’ll take a look at the principal technologies that comprise 4G…

OFDM (Orthogonal Frequency Division Multiplexing): A modulation technique for wireless communications, OFDM was patented by Bell Labs in 1970, and initially was used in a naval communications system dubbed ‘Catherine’. Much like DMT (Discrete MultiTone), OFDM splits the datastream into multiple RF (Radio Frequency) channels, each of which is sent over a subcarrier frequency. DMT and other more conventional techniques encode data symbols for a given data stream onto one radio frequency. In an OFDM system, however, each tone (i.e., frequency) is orthogonal (i.e., independent or unrelated) to the other tones; multiple data symbols are encoded concurrently onto multiple tones in a parallel fashion. The signal-to-noise ratio of each of those very precisely defined frequencies is carefully monitored to ensure maximum performance. OFDM eliminates the requirement for guard bands to separate the frequencies and, thereby, avoid interference from adjacent RF channels. Guard bands are required only around the edges of a set of tones, i.e., RF channels. This yields greater spectral efficiency, as virtually all of the allocated RF spectrum can be used for data transmission.

OFDM is used by the HomePlug Powerline alliance to avoid line noise in a residential power-line network. How it works:

1. Broadband content from cable modem, DSL or satellite is fed to home gateway
2. By plugging gateway into any electrical outlet, content is bridged to any HomePlug-enabled device
3. OFDM takes multiple signals of different frequencies and combines them to form one signal to avoid line “noise”
4. HomePlug network monitors power lines for “noise”.

For more on HomePlug visit their website: http://www.homeplug.org/home

If noise occurs on a particular frequency, OFDM engine shifts transmission to another frequency. OFDM also is used in the IEEE 802.16 WLL specification, also known as WiMax.

4G Mobile Network

4G Mobile Network: 4G is what the next, next generation cellular might be. The idea is simple – universal high-speed Internet access. The thinking is WiFi Internet access (at up to 10 megabits per second) with blanket coverage and fewer base stations than are needed in today’s cell phone networks. Firms including IPWireless, Flarion, Navini, ArrayComm and Broadstorm offer just such a blend. But these are proprietary solutions, so far. Such proposed 4G wireless-broadband systems can be seen in two ways: as a rival to coffee shop WiFi or as a wireless alternative to the cable modem and digital subscriber line (DSL) technologies that now provide broadband access to homes and offices. IPWireless sees their system as a fast internet connection that follows you around. Navini calls it “nomadic broadband”; ArrayComm’s term is “personal broadband”.

Mike Gallagher of Flarion, a firm backed by Cisco, likens WiFi to cordless phones that work within a limited range of a base-station whereas 4G is akin to mobile phones that work anywhere. Advocates of 4G technology argue that, unlike with 3G and WiFi, the business case for 4G is sound. Nobody is sure how commercial WiFi hotspots will make money. The number of connections per day at most hotspots is still tiny. But 4G is being priced like fixed-line broadband, a service for which millions of users worldwide are already willing to pay about $50 a month. 4G networks may be built initially in regions where cable and DSL are unavailable, in order to capitalize on pent-up demand for broadband. Some cell phone companies are said to be considering skipping 3G altogether in favor of 4G.

Source: Newton’s Telecom Dictionary, 2nd Edition; 2006


*4G Developments*

NTT DoCoMo has been testing a 4G system prototype with 4x4 MIMO called “VSF-OFCDM” at 100 MB/sec while moving and 1GB/sec while stationary and is planning on releasing the first commercial network in 2010.

Digiweb, an Irish fixed and wireless broadband company, announced that they have received license from ComReg (Irish Telecom regulator) for the provisioning of 4G mobile communications.

Verizon Wireless announced in September 2007 that it’s planning a joint effort with Vodafone to transition its networks to the 4G standard LTE. In December 2008, Verizon Wireless announced that they intend to build, design, and begin to roll out a LTE network by the end of 2009.

Sprint announced the offering of a 3G/4G connection plan (which is currently only available in Baltimore).

Source: http://en.wikipedia.org/wiki/4G



More on 4G, pervasive networks, and mesh routing to come…stay tuned!

HSDPA (in W-CDMA)

HSDPA (in W-CDMA): High Speed Downlink Packet Access (HSDPA) is a packet-based data service in W-CDMA downlink with data transmission up to 8-10 Mbps (and 20 Mbps for MMO systems) over a 5MHz bandwidth in WCDMA downlink. HSDPA implementations includes Adaptive Modulation and Coding (AMC), Multiple-Input Multiple-Output (MIMO), Hybrid Automatic Request (HARQ), fast cell search, and advanced receiver design. In 3rd generation partnership project (3GPP) standards, Release 4 specifications provide efficient IP support enabling provision of services through an all-IP core network and Release 5 specifications focus on HSDPA to provide data rates up to approximately 10 Mbps to support pack-based multimedia services. MIMO systems are the work item in Release 6 specifications, which will support even high data transmission rates up to 20 Mbps. HSDPA is evolved from and backward compatible with Release 99 WCDMA systems.

3.5G Mobile Network

3.5G Mobile Network: a faster version of 3G wireless networks, 3.5G uses a technology called HSDPA, which is a significant enhancement to W-CDMA and can achieve speeds of up to 14.4 Mbps. HSDPA stands for High Speed Downlink Packet Access. It is a packet based data service feature of the WCDMA standard which provides a downlink with data transmission up to 8-10 Mbps (and 20 Mbps for MIMO systems) over a 5MHz bandwidth in WCDMA downlink. The high speeds of HSDPA is achieved through techniques including; 16 Quadrature Amplitude Modulation, variable error coding, and incremental redundancy. HSDPA is a technology upgrade to current UMTS networks.