LTE Myths

Source : 3GPP

Myth 1: LTE is Data only ?

Reality: LTE supports voice and efficient support of voice was one of the key considerations in designing LTE. The voice solution for LTE is IMS VoIP and it is fully specified.
The 3GPP solution for voice over LTE is a combination of multiple efforts:
The work in Rel 7 to optimize IMS signalling and VoIP encoding so it would be as good or better than CS voice in terms of quality and efficiency,
The work in Rel 8 to develop a radio and core network evolution optimized for the transfer of packet data. The work in Rel-7 to add the IMS emergency call requirements and to adapt it to regulatory requirements in LTE and GPRS in Rel-9. The work in Rel-8 to add the always-on IP connectivity requirements in LTE A key consideration to recognize is that under LTE, voice is just one of many potential media streams that can be communicated. A packet based network and VoIP allows this flexibility while still providing efficient use of radio and network resources.
However, 3GPP recognizes that adoption of both LTE and IMS will not occur overnight. For this reason 3GPP provided a transition solution for voice called CS Fallback. This allows a LTE device to drop back to the legacy 3G or 2G network if IMS VoIP capabilities are not supported. This is viewed as an interim solution to ease the transition to IMS and VoIP.

Myth 2: SMS isn’t supported over LTE

Reality: LTE and EPS will support a rich variety of messaging applications and also SMS is supported over LTE. The solution is twofold, covering both the full IMS case and a transition solution for those networks that do not support IMS.
SMS over IP was fully specified 3GPP Rel 7. It depends on IMS and it is intended to provide compatibility between the existing cellular legacy and the implementations with more elaborate messaging capabilities via SMS and IMS interworking..
For environments without IMS a transition solution was specified. This is called SMS over SGs (previously called the misleading name: SMS over CS). It is a hybrid approach that allows the transmission of native SMS from CS infrastructure over the LTE radio network. SMS over SGs was specified as part of Rel 8. SMS over SGs provides SMS service for mobiles in LTE and since it requires also CS domain infrastructure for the SMS transmission, it is intended to be a transition solution.


Myth 3: IMS isn’t ready for prime time

Reality: IMS has been around a long time. It was first developed as part of Rel 5 in 2002. It is based on IETF protocols such as SIP and SDP that are very mature. These technologies have been embraced by the industry as the signalling mechanism for multimedia applications.
In Rel 7 an effort was made to optimize IMS and the supporting protocols to ensure that voice and other media were supported as efficiently as in circuit switched networks.
IMS is fully specified and mature. The difficulties in rolling out IMS are not due to the protocols or the specifications. The consideration point is not only technical aspects but also shifting the whole industry paradigm from CS services to a truly IP-based environment, i.e. service migration, policies, interoperability and deployment plan included. However, these complexities must be addressed if the idea is to truly provide a richer service environment. This work is ongoing in many forums outside of 3GPP (e.g. Rich Communication Suite).


Myth 4: LTE doesn’t support emergency calls

Reality: VoIP support for emergency calls (including location support) is specified as part of Rel 9. This fulfils the last regulatory requirement separating VoIP from CS in 3GPP networks. A transition solution exists which is falling back to 3G/2G for completing emergency calls. This solution has existed since IMS was introduced (Rel 5).
However, to satisfy the situation of a fallback network not existing, this enhancement was completed in Rel 9. This allows the operator the option of supporting the regulatory requirements for LTE VoIP calls both for phones that can register for normal services and for those in limited service, including the USIM-less case.
Also the emergency call callback from the PSAP and its interaction with the possibly activated supplementary services is specified.

World’s first commercial LTE service launch

TeliaSonera has become the first mobile operator in the world to offer a commercial LTE service, announcing an earlier than expected turn-on of LTE in Stockholm and Oslo on networks supplied, respectively by Ericsson and Huawei.

LTE is expected to be the next major standard in mobile broadband technology, and carriers have begun to convert their networks. Up to another 17 LTE networks are anticipated to be in service by the end of 2010 in the U.S., Canada, Japan, Norway, South Korea, South Africa, Sweden, Armenia and Finland, according to data from the Global Mobile Suppliers Association (GSA).

Meanwhile T-Mobile, Austria and Huawei said they had completed testing of what they claim is the world’s first LTE self organizing network (SON). The tests were carried out in Innsbruck, Austria, and demonstrated the technology’s ability to configure and optimize the network and recover automatically. As a result, Huawei claims an LTE-based SON deployment will offer operators operational cost savings associated with network planning, network deployment and network optimization.

LTE vs WiMAX - does the customer care ?

LTE vs WiMAX, what does it mean to a layman ? Are things gonna change for the better, with seamless broadband data access and which gives us a higher bang for the buck. Why does the FCC take a long time to make the spectrum available, is it a technology roadblock or are we ahead of time ?

This reminds me of the period when broadband providers were making inroads into AOL territory, a decade ago when dialup was the medium of access for internet. The roadrunners', and Comcasts' have come to stay and we cannot imagine a world without broadband ! So in this age of wordplay what matters to a consumer - a technology marvel or the best value for money ?

When AT&T and Verizon publicy shunned WiMAX for LTE, did they make a right choice or succumb to the vendor lobby ? Does speed really matter after a certain point, for example if you are getting 40Mbs for devices used for browsing the internet, would it make any difference if get 60Mbps ? Well all these questions and furthermore intrigue a common user.

Whether they bet on LTE, WiMAX, or some combination of the two, major carriers, hardware companies, and other telecommunications players cannot postpone decisions about their 4G plans–even though it’s not yet clear how the competing technologies will sort themselves out. Investing mammoth amounts of money on building out what may be a temporary technology is high risk–especially during the worst economic crisis since the Great Depression–but they can’t leave the market open to their competitors.

The matter of superiority, WiMAX vs. LTE, is mind-boggling to industry observers, even if it might not be to a genius, or to electrical and wireless engineers. Innovation advocates might see LTE as a natural evolution of technology. Yet some technology writers have described it as unusual, in the logical sequence of technological advancement. At least, the adoption of LTE shows that the best decision, in the acceleration of wireless-connectivity technology, is not to wait for the economic recession to hit rock bottom or reverse.

Here are some typical Myths debunked:

Myth: LTE is backwards compatible with 3G.
Reality: Strictly speaking, backwards compatibility implies that a 3G device can connect to an LTE base station. This is categorically not the case. LTE requires new base stations and new client devices. An HSPA handset will not be able to connect to an LTE base station, period.

Myth: LTE performance is better than WiMAX.
Reality: Because LTE & WiMAX are both based upon OFDMA-MIMO, there is not expected to be a significant performance delta over time. Because WiMAX will have been deployed commercially for over two years before the first LTE network is deployed in 2010, it may have superior performance initially.

Myth: LTE is an evolution of HSPA (3G)
Reality: The 3G evolution from WCDMA to HSPA was achieved via upgrades to operators’ existing 3G networks. LTE is not a 3G upgrade -- it must be deployed in new spectrum and requires a new radio access network (base station hardware, client devices) and connection to a new “all IP” core network (different from today’s 3G core networks.)It is possible to add LTE to existing 2G, 3G cell sites

Myth: Operators will replace their existing 2G/3G networks with LTE.
Reality: We expect operators to maintain their existing 2G or 3G networks for the foreseeable future. These networks are very efficient for voice and have built up good coverage over the years. Similar to WiMAX, LTE will initially be deployed as an overlay data network in new spectrum. Operators will offer multi-mode handsets (e.g,. HSPA + LTE or HSPA + WiMAX) to provide the best of both worlds (coverage + high speed) to their subscribers while they build out their 4G networks over several years.

Myth: WiMAX & 3G are competitors
Reality: We expect WiMAX & 3G to be complementary. Whereas the circuit-switched voice offered by 2G & 3G networks is very efficient, WiMAX provides about 3x more data capacity than today’s 3G networks. This means operators can maintain their existing 2G or 3G network for voice & narrower-band data, and deploy WiMAX for more data intensiveapplications.

Myth: WiMAX will not have as big a device selection as LTE
Reality: Even with the very first commercial Mobile WiMAX network in South Korea, we’ve already seen a level in the variety of devices which exceeds that available for 3G today. For example, one of the most popular form factors for accessing the Wibro network are WiMAX USBdongles with integrated MP3 players and/or storage. PC economics and innovation are backing WiMAX -- so one shouldn’t apply a traditianal “telecom” device model when comparing WiMAX & LTE.

Myth: The LTE standard is complete.
Reality: The LTE standard recently entered a phase where revisions are now under change control -- generally, this phase happens in 3GPP when a spec is 80% complete. The stated 3GPP target for “completion” is October 2008 and then the real work can begin to fix bugs and agree upon interoperable vendor equipment. 3GPP Release 9, a Release that has been functionally frozen in December 2009.

Myth: WiMAX will not have the same economies of scale as LTE.
Reality: Intel’s first generation Wi-Fi + WiMAX embedded module came out at a cost to PC OEMs of less than HALF the cost of 3G-only embedded modules,[1] even though 3G modules are relatively mature. Combine these “PC economics” with the 2+ years of TTM WiMAX has -- during which it will travel down the cost curve -- and we are not expecting to be cost disadvantaged.

Myth: WiMAX & LTE are going to converge.
Reality: Because WiMAX & LTE are so similar, some believe the two should converge. We’re not sure if such convergence will ever get traction, but for now, mobile WiMAX is two to three years ahead of LTE in terms of major commercial deployments and is moving full steamahead.