Матеріали про LTE Technical

Источник: http://feedproxy.google.com/~r/3gAnd4gWirelessBlog/~3/K9SRPm_vOqk/enhanced-uplink-sc-fdma-puschpucch.html.

Its been a while since I blogged about Robust Header Compression (RoHC). You can see the old posts here and here.

I have blogged about Semi-Persistent Scheduling (SPS) and Transmit Time Interval (TTI) Bundling feature before. They are both very important for VoIP and VoLTE to reduce the signalling overhead. It should be noted that as per RRC Specs, SPS and TTI Bundling is mutually exclusive.

Источник: http://feedproxy.google.com/~r/3gAnd4gWirelessBlog/~3/j0evj7QH3Qw/traffic-flow-template-tft-gbr-and-qos.html.

Recently made a combined architecture of LTE with LCS and MBMS and posted it here. This document from MSF below looks at the LoCation Services (LCS) in detail. MSF Whitepaper on Location Services in LTE Networks View more documents from Zahid Ghadialy Источник: http://feedproxy.google.com/~r/3gAnd4gWirelessBlog/~3/xY7gsKPnUW0/location-services-in-lte-networks.html.

Presented in the 3G, HSPA, LTE Optimisation conference, April 2012 by Ljupco Jorguseski. The ICIC presentation referred to in this presentation is available in an earlier post here. LTE deployment and optimisation challenges View more presentations from Zahid Ghadialy Источник: http://feedproxy.google.com/~r/3gAnd4gWirelessBlog/~3/VyOQZbQR5so/lte-deployment-and-optimisation.html.

People who work with LTE Physical layer and maybe higher layers would be aware of this term called 'Antenna Ports'. I have always wondered how these antenna ports are mapped to physical antennas. The following is from R&S whitepaper: The 3GPP TS 36.211 LTE standard defines antenna ports for the downlink.

The following is from NTT Docomo Technical journal:  Three types of radio relay technologies and their respective advantages and disadvantages are shown in Figure 1.  A layer 1 relay consists of relay technology called a booster or repeater. This is an Amplifier and Forward (AF) type of relay  technology by which Radio Frequency (RF) signals received on the downlink from the base station are amplified and transmitted to the mobile station.

Источник: http://feedproxy.google.com/~r/3gAnd4gWirelessBlog/~3/OYcj23FkHN8/v-ideo-td-lte-separation-from-lte-fdd.html.

When a UE registers on a network in 2G/3G or LTE, it has to perform Authentication. The Authentication Vectors are located in the USIM for the device and in Authentication Center (AuC) in the network. Once the Authentication is performed successfully, then the Keys for Ciphering and Integrity are derived and used during the call. As I showed in my earlier post here, It is possible that the same AuC is used for 2G/3G and LTE networks.

Interesting technical whitepaper from R&S: LTE Transmission Modes and Beamforming View more documents from Zahid Ghadialy Available to download from here or here. Источник: http://feedproxy.google.com/~r/3gAnd4gWirelessBlog/~3/bSXBHgh96ec/r-whitepaper-lte-transmission-modes-and.html.

LTE Release 11 Work and Study Items View more documents from Zahid Ghadialy Nice work by Nomor. Available to download from here.

While in the initial testing CSFB timing used to be between 6-8 seconds, most Rel-8 phones can complete the CSFB procedure between 4-4.5 seconds. Unfortunately this is still a lot in terms of signalling.

From the NTT Docomo Technical journal: The LTE handover is broadly divided into a backward handover (PS handover) and forward handover. In the former, the network performs cell switching and notifies the mobile terminal of the destination cell, and in the latter, the mobile terminal performs autonomous switching to pick up the destination cell.