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LteWorld Forum

Discuss any 4G LTE related topic.

S5 Tunnel Management

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I am new to LTEi (and networks alike), have a few questions on the S5i interface:
I was looking at the S5 tunnel creation sequence. I think this is how it goes:

Create Session Request:
SGW->PGW (S5 FTEID has PGW IP/port and TEID for the downlink Tunnel)

Create Session Response:
PGW->SGW (Uplinki TEID in header)

Handover in X2

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I have the following queries:

- What is the advantage of handover interface X2i or interface S10?

- What improvement in the eNodeBi, the handover in interface X2?

- What improvement in the MMEi, the handover in interface X2?

My doubt is whether the handover in the X2 interface is better than the handover interface in S10.

Thank you!!!

In the absence of sgi interface how connection between users in LTE

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Please provide me solution for this question "In the absence of sgi interface how connection between users in LTEi?"

Please provide me spec. no also if available.

How does eNodeB identify that interference is happening in PDCCH region so that it can start eICIC?

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How does eNodeBi identify that interference is happening in PDCCH region so that it can start eICIC? I mean there are two scenarios
1. when only PDSCH region has interference and not PDCCH region.
2. when both PDCCH and PDSCH region has interference.

In first case Rel8(frequency domain) ICIC is sufficient, but in case two it will require eICIC.

LTE Resource Mapping

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I'm a novice to LTEi. During my studies, I had this doubt and I thought of putting it here for some clarifications in the LTE Resource mapping side. I want to know how is the data( in bits) getting mapped onto the RE's. Is it like first all the 12 sub-carriers of the zeroth symbol in the RBi is filled up and then the 12 sub-carriers of the first symbol??

comparison of open source LTE implementations/ LTE SDRs

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Hi all,

Has anybody compared open source LTEi implementations? For example
1. openLTE (http://sourceforge.net/projects/openlte/)
2. Flexnets Aloe (https://github.com/flexnets/aloe/wiki)

There are many more but do not know which one to start with. Any suggestions are welcome. Here's a compilation: http://myriadrf.org/open-source-lte/ but its not detailed.

Ra.

rate matching in UCI HARQ or RI + PUSCH

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Dear Experts,

I have a question on how different coding rates are achieved in case of UCI HARQi and RI when they are sent along with PUSCH.

In section 5.2.2.6 of 36-212 specification document, the parameter Qprime would give the number of coded symbols required for UCI HARQ.

Questions regarding handover procedures, load management and protocol stack in LTE system

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Hello,

I have questions regarding handover procedures, load management and protocol stack in LTEi system:

1. Does the LTE support "Network Initiated and Network controlled handover" or it only supports "Terminali assisted and networked controller handover"?
If yes, could you please specify the 3GPPi specifications which explains the signaling procedures for that.

Data traffic offloading

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Hi,
I'm currently working on the data offloading techniques in lte. It will be great if anyone can help me to understand the answers for the following queries in the offloading to WiFi from lte.
1.After registering with the trusted WiFi network,will the ue context maintained in mme.
2. Is that the traffic alone is offloaded to WiFi and the control plane still remains in mme

Deployement of CSG / HeNBs

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Hi,

I am currently studying about the closed subscriber group cells,
I want to know if any of the operator has already started deploying the CSGi Cells ?

If so what would be the deployement strategy in brief considering there is a lot of confusion in the current specifcation regarding the manual CSG selection.

My main doubts are whether :

Synchronization on Uplink signal

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Hi

I would like to know how to do synchronization on lte uplink signal. I have lte signal generator and card that samples the signal. now i want to verify that the signal i have from sampling is valid uplink (PUSCH) signal.
What are the approaches for that problem?

thanks

ROHC feedback in PDCP

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Hi,

I am using a library from "rohc-lib.org", for ROHC in PDCP. But the library is using piggybacked feedback packets. In PDCP spec there is a control PDUi given for interspersed ROHC feedback packet.

Is it a must to use interspersed ROHC feedback packet for PDCP instead of using piggybacked one ?

Resource Reservation Usage

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Hi, I've read a fair amount on reservation in IMS. Does anyone happen to be aware if this is actually used for current cell phone applications?

FRESH a 32-bit random input to the UIA2 function

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in PDCP, EIA1 used for integrity protection(33.401 B2.2), is based upon "UEA2 and UIA2 Algorithm Specifications." In UIA2 spec, a value called "FRESH" s used which is specified in UIA2 spec as "32-bit random input to the UIA2 function". If it is a random number, how would the peer entity know about its value ?

What is LTE REG Resouce element group?? Any one explain please

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Explain LTEi Resouce element group