Telecommunications Blog

The following essential landmark may be the standardization associated with LTE-Advanced (LTE Rel. 10 and beyond). To ensure that the actual mobile telecoms technologies will be able to come up with technology that could contend, you ought to make sure that brand new mobile technology are now being developed as well as created. This is actually the thinking at the rear of beginning the introduction of the brand new LTE-Advanced techniques, showing the actual technologies as well as building the actual LTE-Advanced requirements.


 While LTE's peak downlink speed is theoretically 300 Mbps, LTE-Advanced can ostensibly reach 1 Gbps but realistically would get only 100 Mbps in everyday use. LTE's uplink peak rates of 75 Mbps pale in comparison to LTE Advanced's 500 Mbps.
 Along with function beginning upon LTE-Advanced, numerous crucial specifications as well as crucial functions tend to be visiting lighting. While not set however within the specs, there are lots of higher level is designed for your brand new LTE-Advanced standards. These types of will have to become confirmed and far function continues to be carried out within the specs prior to they are almost all set. 

Presently a few of the primary heading is designed with regard to LTE-Advanced is visible beneath :-

1. Peak data rates : downlink - 1 Gbps; uplink - 500 Mbps.
2. Spectrum efficiency : 3 times greater than LTE.
3. Peak spectrum efficiency : downlink - 30 bps/Hz; uplink - 15 bps/Hz.
4. Spectrum use: the ability to support scalable bandwidth use and spectrum aggregation where non-contiguous spectrum needs to be used.
5. Latency : from Idle to Connected in less than 50 ms and then shorter than 5 ms one way for individual packet transmission.
6. Cell edge user throughput to be twice that of LTE.
7. Average user throughput to be 3 times that of LTE.
8. Mobility : Same as that in LTE
9. Compatibility : LTE-Advanced shall be capable of interworking with LTE and 3GPP legacy systems. 

LTE-Advanced would to be moving in numerous areas within 2013, along with suitable devices as well as gadgets growing together with this particular release.

This is a listing of businesses that are offering LTE technologies associated parts.

Its full name is 3GPP Long Term Evolution for the Universal Mobile Telecommunications System, or 3GPP UMTS LTE for short. LTE (Long Term Evolution) is a wireless broadband technology designed to support roaming Internet access via cell phones and handheld devices.


Where the current generation of mobile telecommunication networks are collectively known as 3G, LTE is marketed as 4G.


Requirements :


LTE Specifications :



 LTE uses two different types of air interfaces (radio links), one for downlink (from tower to device), and one for uplink (from device to tower).For the downlink, LTE uses an OFDMA (orthogonal frequency division multiple access) air interface For the uplink (from device to tower), LTE uses the DFTS-OFDMA (discrete Fourier transform spread orthogonal frequency division multiple access) scheme of generating a SC-FDMA (single carrier frequency division multiple access) signal. 

The major difference between the OFDMA signal for downlink and the SC-FDMA signal for uplink is that it uses a discrete Fourier transform function on the data to convert it into a form that can be used to transmit.

LTE air interface adopts OFDMA (orthogonal frequency division multiple access) for the downlink and SC-FDMA (single-carrier frequency domain multiple access) for the uplink. It employs AMC (adaptive modulation and coding) as well as a number of optional MIMO (multiple-input multiple-output) antenna techniques and interference management methods for potential performance enhancements.

Telecommunications Blog

One of the first things to note about LTE is the integration between the Frequency Division Duplex (FDD) and Time Division Duplex (TDD) radio access modes. In the previous Universal Mobile Telephone System (UMTS) specifications, which also supported FDD and TDD, the RF specifications for the UE FDD, UE TDD, base station FDD and base station TDD modes were covered in separate documents.

However, the early decision by 3GPP to fully integrate FDD and TDD modes for LTE has resulted in only one RF specification document each for the UE and the eNB. With the higher level of integration between the two modes, the effort required to support them should be less than it was in the past.

Channel Bandwidths:

LTE was designed from the start to support six different channel bandwidths. These are 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz. In addition to this the subcarriers are spaced 15 kHz apart from each other. To maintain orthogonality, this gives a symbol rate of 1 / 15 kHz = of 66.7 µs.

Earlier versions of the specifications also supported 1.6 MHz and 3.2 MHz for interworking with LCR TDD, but these were removed when the LTE TDD frame structure was aligned with the FDD frame structure rather than the TD-SCDMA frame structure from UMTS.

  Both are 4G technologies designed to move data rather than voice. Both are IP networks based on OFDM (Orthogonal Frequency Division Multiplexing) technology.

   WiMax is based on a IEEE standard (802.16),Depending on the spectrum alloted for WiMax deployments and how the network is configured, this can mean a WiMax network is cheaper to build.

     WiMAX offers peak wireless data speeds of up to 60 Mbps on the downstream and 25 Mbps for sending data upstream.

    Long Term Evolution (LTE), can ferry data to you at download speeds of 100 Mbps and support upload speeds of 50 Mbps.

    That means you can download about two 5-minute MP3 files every second. Think about that. Sure, it would only take WiMAX about seven minutes to download a single 5-minute MP3 file, which is still fast, but it’s nowhere near the theoretical scale of LTE.

7th LTE World summit is schedule on 17-18 May 2011 at Amsterdam RAI.




Features of this event will be :

Now in its 7th Year! This is THE LTE event of the year!

• 2500+ Attendees from 100+ countries
• 150+ High-level speakers
• 120+ Exhibitors, meeting rooms & hospitality suites
• 100+ Operator Case Studies
• 50%+ Director-level and above attendance - meet the decision makers here!

SC-FDMA (Single Carrier Freq Domain Multiple Access) used in Up-Link in LTE.

    o The system uses SC-FDMA as uplink multiple access method instead OFDMA to decrease the PAPR and power requirements.

    o It offers the same degree of multipath mitigation but because the transmission is
on single carrier PAPR is lower.


     o The basic idea is to add cyclic prefix to the mapped symbols and in the receiver
multipath distortion can be handled by the same method as OFDM (carrier based equalization).

   LTE technology supports manufacturer’s rated peak download speeds of up to 150 megabits per second (Mbps) and upload speeds of up to 70 Mbps.

   Canadian operator TELUS has announced the plan to launch of LTE network 1st H 2012. Following field testing in 2011 and the completion of an RFP process currently underway, construction on TELUS' LTE network will begin in the latter half of 2011 in major urban markets across Canada. 

   Telus – the country’s third-largest operator – said that construction of the new network will begin in the latter half of 2011 in “major urban markets” across Canada. It will initially operate on

   Virginia-based nTelos Wireless and Alcatel-Lucent have accomplished an end-to-end Long Term Evolution (LTE) field trial in Waynesboro, Va.

   “This trial enables us to make informed decisions on how to smoothly evolve our network and incorporate 4G LTE into the existing infrastructure, particularly in terms of end-user performance, throughput, latency and Quality of Experience,” said Bobby McAvoy, Senior Vice President, Wireless Engineering & Operations for nTelos Wireless.

   For this trial, Alcatel-Lucent provided an end-to-end integrated solution including 4G LTE base

    Infrax Systems, Inc. (OTCBB: IFXY), a global provider of unified Smart Grid-related products and services for the Energy and Utility industries, today announced the availability of a new upgradeable WiMAX/LTE base station. This new base station option allows network operators and service providers to utilize the desirable 1.4-1.6 GHz frequencies. The addition of these new base stations will provide operators of rural broadband networks better range than the typical 2.5 or 3.5 GHz WiMAX. These new base stations also have the capability of being upgraded from WiMAX (802.16e) to Long Term Evolution (LTE) via firmware. These modular 4G base stations can even provide the ability to change to a different frequency by changing radio modules to provide more longevity of the platform and protect network operator's investments.

   The American Reinvestment and Recovery Act appropriated $7.2 billion for the Department of Agriculture’s Rural Utilities Service (RUS) and the Department of Commerce’s National

   China Mobile has selected Ericsson to participate in the world’s largest TD-LTE trial network deployment to date. With the approval of the Chinese Ministry of Industry and Information Technology (MIIT), Ericsson will build trial network in the city of Shenzhen.

   The approval by MIIT follows the successful completion of interoperability tests of Ericsson's TD-LTE network equipment with multiple chipset manufacturers. As part of its efforts to further develop the global ecosystem, Ericsson is proactively conducting interoperability tests with leading international players such as ST-Ericsson and Qualcomm.

  "China Mobile has always been a formidable force in driving the evolution of telecommunications technologies. As a longtime strategic partner to China Mobile, Ericsson will fully support our customer in its tremendous endeavor to make TD-LTE a reality in the

   Epitiro has completed the independent speed, latency and voice quality-of-experience analysis on a commercially available LTE network. Tests recorded peak broadband download speeds of 48Mbps (36.1Mbps mean) where as Mean latency was just 23ms.

  Epitiro, at the same time, tested TeliaSonera's legacy 3G network; LTE delivered mean download speeds nine times faster, and its latency was five times faster. Analysis of IP calls to the UK, made using voice over LTE (VoLTE), found the quality to be ‘excellent’ on average with only 1 call in 298 being of inferior quality.

  “Based on our observations, this LTE rollout is directly comparable to high-speed fixed

LTE PHY layer block diagram:-

We can implement LTE Physical layer Block diagram in Matlab .



Frame structure: it is FDD frame which is 10ms divided into 10 subframes each
of 1ms & each subframe is divided into 2 slots of 0.5 ms which carry 6 or 7 OFDM
symbol.

EPS to EPC

   A key feature of the EPS is the separation of the network entity that performs control-plane functionality (MME) from the network entity that performs bearer-plane functionality (SGW) with a well defined open interface between them (S11).


LTE S11: -

    An IP interface between MME and SGW! GTPv2 is the protocols used at the application

What is LTE?

    3GPP LTE (Long Term Evolution) is the name given to a project that aims to improve the
UMTS mobile phone and it is not a standard but it will result in the release 8 of UMTS
and it can be considered the real 3.9G & invited to join the 4G family.

Technical specifications:-


LTE PHY layer block diagram:-