Tuesday, April 3, 2012

Pros and Cons of LTE

Advantages of LTE
  • Facilitates the current applications to perform on better speed as well as for the new mobile applications
  • Decreases the traffic of communication in term of sending data.
  • Allows more users to use the same frequency that result in increasing of Mobile Broadband users.
  • Separates frequencies into different channel in order to protect the disturbance of each channel; the solution was called “Orthogonal”.
  • Offers faster data rate transfer as compare to existing 3G network equipments by using radio waves over the same bandwidth.
  • Supports more data capacity because it focuses on VoIP(Voice Over Internet Protocol).
  • Allows wireless broadband providers to transition to this new technology without rebuilding their entire networks from the ground up.
  • Supports voice and Short Message Service (SMS) text messaging using existing networks via Generic Access (VoLGA).


Disadvantages of LTE
  • Start-up costs of service providers and consumers for equipment upgrades are too high; new equipments will be needed to be installed.
  • Need to use additional antennas at network base stations for data transmission. As a result to the network upgrades users need to buy new cell phones to make use of new network infrastructure.


Comparison Between LTE and WiMAX

Here's a website which I think it's quite useful for those who wish to know the difference between long term evolution (LTE) and WiMAX:

LTE and WiMAX Comparison

LTE Architecture Overview

The evolved architecture comprises E-UTRAN (Evolved UTRAN) on the access side and EPC (Evolved Packet Core) on the core side. In E-UTRAN, eNBs provide the E-UTRA user plane protocols (PDCP/RLC/MAC/PHY) and control plane (RRC) protocol which terminates towards the UE.

The eNBs are interconnected with each other by means of the X2 interface. The eNBs are connected by the S1 interface to the EPC (Evolved Packet Core). The eNB connects to the MME (Mobility Management Entity) by means of the S1-MME interface and to the Serving Gateway (S-GW) by means of the S1-U interface. The S1 interface supports a many-to-many relation between MMEs / Serving Gateways and eNBs.


LTE Network Elements

eNB

eNB interfaces with the UE and hosts the PHYsical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Control Protocol (PDCP) layers. It also hosts Radio Resource Control (RRC) functionality corresponding to the control plane. It performs many functions including radio resource management, admission control, scheduling, enforcement of negotiated UL QoS, cell information broadcast, ciphering/deciphering of user and control plane data, and compression/decompression of DL/UL user plane packet headers.

Mobility Management Entity

Mobility management entity manages and stores UE context (for idle state: UE/user identities, UE mobility state, user security parameters). It generates temporary identities and allocates them to UEs. It checks the authorization whether the UE may camp on the TA or on the PLMN. It also authenticates the user.

Serving Gateway

The SGW routes and forwards user data packets, while also acting as the mobility anchor for the user plane during inter-eNB handovers and as the anchor for mobility between LTE and other 3GPP technologies (terminating S4 interface and relaying the traffic between 2G/3G systems and PDN GW).

Packet Data Network Gateway

The PDN GW provides connectivity to the UE to external packet data networks by being the point of exit and entry of traffic for the UE. A UE may have simultaneous connectivity with more than one PDN GW for accessing multiple PDNs. The PDN GW performs policy enforcement, packet filtering for each user, charging support, lawful Interception
and packet screening.


The figure below shows the evolved system architecture:




Here's a video briefing about the LTE architecture:

Long Term Evolution (LTE) Video

What exactly is LTE?

LTE is the next step in wireless technology, and it's expected to be the mobile broadband platform for new services and innovation for the foreseeable future. 3G LTE is next generation step in mobile communications with the promise of peak download rates of at least 100 Mbit/s and upload rates 50 Mbit/s. Learn more about LTE and how AT&T 4G LTE allows you to stream, download, upload, browse and game faster than ever before.


Here's a video to help you all to understand better about LTE:



Another video about LTE:

Monday, April 2, 2012

What is Long Term Evolution (LTE)?


Overview

Long Term Evolution (LTE) is a 4G wireless broadband technology developed by the Third Generation Partnership Project (3GPP), an industry trade group. 3GPP engineers named the technology "Long Term Evolution" because it represents the next step (4G) in a progression from GSM, a 2G standard, to UMTS, the 3G technologies based upon GSM.

LTE is part of the GSM evolutionary path for mobile broadband, following EDGE, UMTS, HSPA (HSDPA and HSUPA combined) and HSPA Evolution (HSPA+). Although HSPA and its evolution are strongly positioned to be the dominant mobile data technology for the next decade, the 3GPP family of standards must evolve toward the future. HSPA+ will provide the stepping-stone to LTE for many operators.

The overall objective for LTE is to provide an extremely high performance radio-access technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. Because of scalable bandwidth, operators will be able to easily migrate their networks and users from HSPA to LTE over time.


Features

LTE capabilities include:
  • Downlink peak data rates up to 326 Mbps with 20 MHz bandwidth
  • Uplink peak data rates up to 86.4 Mbps with 20 MHz bandwidth
  • Operation in both TDD and FDD modes
  • Scalable bandwidth up to 20 MHz, covering 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz in the study phase
  • Increased spectral efficiency over Release 6 HSPA by two to four times
  • Reduced latency, up to 10 milliseconds (ms) round-trip times between user equipment and the base station, and to less than 100 ms transition times from inactive to active


Basic Knowledge of 4G


In telecommunications, 4G is the fourth generation of cellular mobile communications standards. It is a successor of the third generation (3G) standards. A 4G system provides mobile ultra-broadband Internet access, for example to laptops with USB wireless modems, to smartphones, and to other mobile devices. Conceivable applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing and 3D television.

Two 4G candidate systems are commercially deployed: The Mobile WiMAX standard (at first in South Korea in 2006), and the first-release Long term evolution (LTE) standard (in Scandinavia since 2009). It has however been debated if these first-release versions should be considered as 4G or not.

Carriers that use orthogonal frequency-division multiplexing (OFDM) instead of time division multiple access (TDMA) or code division multiple access (CDMA) are increasingly marketing their services as being 4G, even when their data speeds are not as fast as the International Telecommunication Union (ITU) specifies. According to the ITU, a 4G network requires a mobile device to be able to exchange data at 100 Mbit/sec. A 3G network, on the other hand, can offer data speeds as slow as 3.84 Mbit/sec. From the consumer's point of view, 4G is more a marketing term than a technical specification, but carriers feel justified in using the 4G label because it lets the consumers to expect significantly faster data speeds.

When fully implemented, 4G is expected to enable pervasive computing, in which simultaneous connections to multiple high-speed networks will provide seamless handoffs throughout a geographical area. Coverage enhancement technologies such as femtocell and picocell are being developed to address the needs of mobile users in homes, public buildings and offices, which will free up network resources for mobile users who are roaming or who are in more remote service areas.