A Primer on LTE – link on wikipedia

Our post on “A Primer on LTE” is now referenced on wikipedia on the main LTE page :

http://en.wikipedia.org/wiki/Long_Term_Evolution

Let us know your feedback. Thanks for the excellent feedback on a similar post on “Primer on WiMAX” and referenced on wikipedia on the main WiMAX page.

A Primer on WiMAX – see our post referenced on wikipedia

Our article on “A Primer on WiMAX” was liked so much that a link to it was created on wikipedia under Notes and References section of the main WiMAX page :

http://en.wikipedia.org/wiki/WiMAX

Thanks to the team or individual who put our post on wikipedia. So we have decided to create “A Primer on LTE”. LTE is the competing 4G technology and coming a little later than WiMAX. Stay tuned for the LTE primer on this blog.

Mobile Backhaul Network

Attended a webinar today on Mobile backhaul networks conducted by Wireless Week magazine (www.wirelessweek.com). There is plenty of debate on what kind of backhaul works best for emerging 4G wireless techs ie WiMAX or LTE. Folks from Juniper and France Telecom/Orange and some others argue that an IP/MPLS (Multi-protocol Label Switching) backbone is a great solution for a broadband mobile backhaul. Their reasoning :

• MPLS is good mobile back haul for 2G, 3G,  LTE and WIMAX with both IPv4 and IPv6 traffic
  • Supports flexible connectivity and configuration models
• MPLS is future proof due to its flexibility
  • Can support whatever 4G networks come up with
• Mobile backhaul requires flexibility due to other reasons as well
  • Many technologies co-exist
  • Multiple deployment scenarios co-exist

MPLS has delivered in landline networks. It is adaptable and hence a good candidate for mobile backhaul. One does not know how mobile backhaul evolves so it is better to position a flexible tech like MPLS for mobile backhaul to accommodate the various configurations which 4G folks come up with.

Our take – Juniper and similar firms have invested heavily in MPLS equipment, so this standard fits them naturally. If we talked to the WiMAX equipment folks, they would like a wireless WiMAX-based backhaul. Fiber manufacturers would like a predominance of a fiber-based backhaul. Really, all of these are viable backhaul solutions.

MT

A Primer on WiMAX

This is our first content post. We thought we will start with something which is a hot topic nowadays in wireless world everywhere. This has to do with whether the new WiMAX technology is going to make it or not.

Well – we have seen many obituaries written on WiMAX. But it seems to persist in large pockets of the world and there are real projects being done and real money being made in WiMAX. Some of the large installations include Unwired in Australia which started with a Navini Networks (now Cisco) solution way back in 2003. Unwired is a large wireless broadband provider in some metros in Australia and has done fairly well with a WiMAX strategy. Reliance, Airtel and Tata all are deploying regional WiMAX in various metros of India. We see projects in Middle East, Sprint’s Xohm service trials in United States, several projects in Latin America. So next time somebody tells me that WiMAX is a dying technology, I take it with a pinch of salt.

What is WiMAX

WiMAX (worldwide interoperability for microwave access) is a 4G wireless technology having service capabilities in regulated and unregulated spectrum (though our customers and OEM partners are slowly moving away from using WiMAX in unregulated spectrum).  WiMAX comes from IP / microwave side similar to its cousin WiFi (which is from IP world) as opposed to HSPA, GPRS and UMTS which are GSM flavors of 2.5G/3G wireless tech. The 4G version in GSM evolution path is LTE (Long Term Evolution) – something which is two years away but gaining traction with largest mobile operators in the world eg AT&T and Verizon in USA have announced intention to adopt LTE rather than try WiMAX. But WiMAX has a first mover advantage as it is available with large OEM and vendor support. So many folks around the world are trying this rather than wait out for a full-blown LTE rollout in another 2 years or so.

Why WiMAX

WiMAX allows speeds of 2-4 Mbps in early trials on the downlink and 1-2 Mbps on the uplink in wireless communications from mobile phones, laptops, WiMAX CPE (customer modems) etc, in effect matching the DSL or lower end cable modem speeds of today. WiMAX offers personal broadband to folks who want high speed wireless connectivity anywhere, anytime. Of course one needs WiMAX compatible chip sets in laptops or WiMAX enabled phones for the mobility aspect of it. For home or office use, WiMAX can be deployed as a modem (called a CPE or customer premise equipment) inside or outside a home or building. WiMAX equipment can communicate with WiMAX base stations in cell towers several miles away without signal degradation. As a result, we are talking about high speed wireless mobile TV, multimedia gaming, streaming media, P2P apps, VOIP etc.

WiMAX standards are administered by a body called the WiMAX Forum which describes WiMAX as “a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL”.

WiMAX offers non- line-of-sight communication between Base Station and the customer CPE which is a great practical advantage and makes it a viable competitor to DSL or cable.

WiMAX Technology

There are two flavors of WiMAX – Fixed WiMAX and Mobile WiMAX – they are based on IEEE 802.16d and 802.16e specification respectively. In simple terms, Fixed WiMAX allows a cable or DSL line substitute but no mobility or roaming between cells. Mobile WiMAX allows mobility and handoff between Base Stations so can operate like a true wireless network.

Typically, WiMAX is being deployed in the 2.5-2.7 GHz range in USA and 3.3-3.5 GHz range in Europe and Asia but there are exceptions to this rule.

WiMAX involves the following equipment – Base Stations on cell towers and CPE or customer premise equipment or receivers. CPE are similar to our DSL modems or cable modems or can be externally installed equipments. In-building/In-home WiMAX modems promise to revolutionize broadband access for homes and businesses and serve as a compelling replacement for DSL or cable internet subscribers.

Intel has made available WiMAX chips in laptops (though we hear different versions as to level of interest of Intel in this area). As to mobile phones, several mobile phone manufacturers have announced intention to make WiMAX phones in large numbers.

WiMAX is a last mile wireless access solution. It needs a backhaul network or the core transmission over a large area – the backhaul can be T1 lines from local TELCOs, line-of-sight WiMAX towers themselves or even satellite communications for remote areas. WiMAX does require more advanced backhaul than traditional wireless networks hence fiber-based backhaul or microwave point-to-point backhaul is very appropriate for WiMAX.

Other 4G technologies

LTE (Long Term Evolution) is the most prominent threat to WiMAX technology. LTE is the 4G flavor of GSM evolution path and hence more likeable by GSM carriers and some major CDMA vendors around the world. Since GSM is the dominant standard in the world in wireless networks, LTE is seen as a likely winner in 4G space especially among large operators around the world. Mobile WiMAX has had trials in 10Mbps range (over a 10Km distance) but Nokia has done trials of LTE in which it has achieved 100 Mbps data transfer speeds with LTE equipment.

UMB or Ultra Mobile Broadband is the CDMA version of 4G developed by Qualcomm which also promotes the CDMA standard. Verizon Wireless, the giant CDMA operator in United States, shocked the world when it announced an intention to migrate to LTE instead of UMB in the 4G evolution. Verizon may still go the UMB-way; we will see how this plays out. UMB can achieve the same speeds as LTE for wireless broadband access.

Interested in more on WiMAX and LTE..stay tuned for further posts and CellStrat white papers which will discuss this topic more extensively. Meanwhile we would love to get your thoughts or feedback on this interesting new space..

TR