tag:blogger.com,1999:blog-65563134959779815192024-03-13T05:10:23.472+05:30Learning LTEArticles, updates on LTE from 3GPP standard specificationsVikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.comBlogger65125tag:blogger.com,1999:blog-6556313495977981519.post-74029920463312360722018-11-02T14:29:00.004+05:302018-11-02T14:30:39.577+05:30LTE SON Blog
https://lte-son.blogspot.com/
1. Introduction
2. SON Architecture
3. RACH Optimization
4. SON Features
5. Coverage & Capacity Optimzation
Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-635852175811569092016-07-14T19:02:00.001+05:302016-07-14T19:03:51.805+05:30Low Power Wide Area Networks
To support the further growth and development of the Internet of Things (the IoT) the mobile industry is developing and standardizing a new class of GSM technologies. These Low Power Wide Area (LPWA) networks will support devices requiring low mobility, low power consumption, long range, low cost and security.
Low Power Wide Area (LPWA) networks will play an important role in connecting up Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-33377335011595377822015-09-18T14:52:00.001+05:302015-09-18T14:53:15.472+05:30Self-Organizing Networks - SON
SON solutions can be divided into three categories: Self-Configuration, Self-Optimisation and Self-Healing. The SON architecture can be a centralized, distributed or a hybrid solution.
SELF-CONFIGURATION
This is the dynamic plug-and-play configuration of newly deployed eNBs. The eNB will by itself configure the Physical Cell Identity, transmission frequency and power, leading to faster Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com5tag:blogger.com,1999:blog-6556313495977981519.post-83366950118663928272013-06-20T15:16:00.000+05:302013-06-20T15:16:51.629+05:30LTE Radio Quality Indicator's
The LTE standard defines three quality indicators that serve
as a benchmark for the transmission quality in the downlink:
CQI, PMI and RI (channel state information – CSI). The
user equipment (UE) can measure all three and transmit the
information in the uplink to the base station (BS), which then
adapts the signal transmission in the downlink accordingly,
although this is not mandatory. To Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com4tag:blogger.com,1999:blog-6556313495977981519.post-87803713519641746882012-08-24T23:28:00.000+05:302012-08-24T23:28:53.767+05:30Backoff Indicator
Backoff Indicator is a special MAC subheader that carries the parameter indicating the time delay between a PRACH and the next PRACH.
There are cases where a UE has to send another PRACH after it already sent a PRACH.
The most common cases are as follows.
i) UE sent a PRACH but didn't get a RAR for some reason.
ii) UE sent a PRACH and got RAR, but the RAPID in Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-66422994896811114772012-04-17T12:07:00.000+05:302012-04-17T12:08:05.216+05:30Services Provided by Physical (L1) Layer
The physical layer offers data transport services to higher layers. The access to these services is through the use of transport channels via the MAC sub-layer. A transport block is defined as the data delivered by MAC layer to the physical layer and vice versa. Transport blocks are delivered once every TTI (Transmission Time Interval).
The physical layer is expected to perform the Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com1tag:blogger.com,1999:blog-6556313495977981519.post-23244173809790155792012-04-12T23:01:00.000+05:302012-04-12T23:02:06.454+05:30Reference signals
Five types of downlink reference signals are defined:
- Cell-specific reference signals (CRS)
- MBSFN reference signals
- UE-specific reference signals (DM-RS)
- Positioning reference signals (PRS)
- CSI reference signals (CSI-RS)
There is one reference signal transmitted per downlink antenna port.
Cell-specific reference signals
Cell-specific reference signals shall be Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com1tag:blogger.com,1999:blog-6556313495977981519.post-64663991994595966852012-03-09T14:33:00.000+05:302012-03-09T14:33:00.787+05:30Radio Channel Quality Feedback
CQI (channel quality indicator)
CQI is an indication of the downlink mobile radio channel quality as experienced by this UE. Essentially, the UE is proposing to the eNodeB an optimum modulation scheme and coding rate to use for a given radio link quality, so that the resulting transport block error rate would not exceed 10%. 16 combinations of modulation scheme Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-37549385192477366922012-03-05T11:07:00.000+05:302012-03-05T11:07:00.151+05:30RRM functions
Radio Bearer Control (RBC)
The establishment, maintenance and release of Radio Bearers involve the configuration of radio resources associated
with them. When setting up a radio bearer for a service, radio bearer control (RBC) takes into account the overall
resource situation in E-UTRAN, the QoS requirements of in-progress sessions and the QoS requirement for the new
service. RBC is also Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-32117050873842347222012-03-01T13:49:00.000+05:302012-03-01T13:50:48.322+05:30PDCCH and PUCCH
Physical Downlink Control Channel (PDCCH)
The downlink control signalling (PDCCH) is located in the first n OFDM symbols where n ≤ 4 and consists of:
- Transport format and resource allocation related to DL-SCH and PCH, and hybrid ARQ information related to
DL-SCH;
- Transport format, resource allocation, and hybrid-ARQ information related to UL-SCH;
Transmission of control Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-67965957327345264752012-02-16T17:46:00.001+05:302012-02-16T17:48:18.215+05:30RSRP and RSRQ
In cellular networks, when a mobile moves from cell to cell and performs cell selection/reselection and handover, it has to measure the signal strength/quality of the neighbor cells. In LTE network, a UE measures two parameters on reference signal: RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality).
RSRP is a RSSI type of measurement. It measures the averageVikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com4tag:blogger.com,1999:blog-6556313495977981519.post-13714620073487366502012-01-03T11:19:00.000+05:302012-01-03T12:11:09.367+05:30UE Identity's in LTE
Globally Unique Temporary Identity (GUTI)
GUTI is allocated to the UE by the MME and has two components GUMMEI (Globally Unique MME ID) and the M-TMSI (MME-TMSI). The GUMMEI identifies the MME.When contacting the network, the mobile sends the GUTI to the base station which then uses the parameter to identify the MME to which it will send the request to re-establish the communication session.&Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-7797767649417656062011-12-08T12:10:00.001+05:302011-12-19T11:02:43.695+05:30SC-FDMA Modulation
Modulation symbol mapping
The transmitter of an SC-FDMA system converts a binary input signal to a sequence of modulated subcarriers. Todo so, it performs the signal processing operations shown in the Figure. Signal processing is repetitive in a few different time intervals. Resource assignment takes place in transmit time intervals (TTIs). In 3GPP LTE, a typical TTI is 0.5 ms. The TTI is Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-17572275570244558152011-12-08T11:36:00.001+05:302011-12-19T11:03:00.914+05:30LTE SC-FDMA
For the LTE uplink, a different concept is used for the access technique. Although still using a form of OFDMA technology, the implementation is called Single Carrier Frequency Division Multiple Access (SC-FDMA).
Single carrier frequency division multiple access (SC-FDMA) has been adopted by the third generation partnership project (3GPP) for uplink transmission in technology standardized Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-47674502206321308892011-10-12T11:14:00.000+05:302011-10-12T11:15:39.057+05:30QoS Class Identifier (QCI)
The need for supporting a broader variety of applications requiring higher bandwidth and lower latency led 3GPP to alleviate the existing QoS principles with the introduction for EPS of a QoS Class Identifier (QCI).
The QCI is a scalar denoting a set of transport characteristics (bearer with/without guaranteed bit rate, priority, packet delay budget, packet error loss rate) and used to infer Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com1tag:blogger.com,1999:blog-6556313495977981519.post-88570150748350100192011-07-26T20:57:00.001+05:302011-07-26T20:58:26.041+05:30IP address allocation
A UE performs the address allocation procedures for at least one IP address (either IPv4 address or IPv6 prefix) after the default bearer activation if no IPv4 address is allocated during the default bearer activation.
One of the following ways is used to allocate IP addresses for the UE:
a) The HPLMN allocates the IP address to the UE when the default bearer is activated (dynamic or Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com2tag:blogger.com,1999:blog-6556313495977981519.post-806270116466393112011-07-20T21:39:00.001+05:302011-07-20T21:46:01.511+05:30NAS Attach RequestThe UE initiates the Attach procedure by the transmission, to the eNodeB, of an Attach Request. Following parameters are included in this message.
IMSI or old GUTI, last visited TAI (if available), UE Core Network Capability, UE Specific DRX parameters, Attach Type, ESM message container (Request Type, PDN Type, Protocol Configuration Options, Ciphered Options Transfer Flag), KSIASME, NAS Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-69655777219591242182011-04-16T15:30:00.000+05:302011-04-16T15:30:47.139+05:30UE Radio Capability HandlingThe UE Radio Capability information contains information on RATs that the UE supports (e.g. power class, frequency bands, etc). Consequently, this information can be sufficiently large (e.g. >50 octets) that it is undesirable to send it across the radio interface at every transition from ECM IDLE to ECM CONNECTED. To avoid this radio overhead, the MME stores the UE Capability information Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com1tag:blogger.com,1999:blog-6556313495977981519.post-25924159327918062622011-03-22T21:49:00.001+05:302011-03-22T21:52:10.762+05:30Functions of various CSFB architectural elementsMobility Management Entity (for GERAN/UTRAN CSFB)
o Multiple PLMN selection and reselection for the CS domain
o Deriving a VLR number and LAI from the TAI of the current cell and based on the selected PLMN for CS domain, or using a default VLR number and LAI
o For CS fallback, generating a TAI list such that the UE has a low chance of "falling back" to a cell in a LA different to the Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-25505338234566761272011-03-01T22:40:00.002+05:302011-03-10T15:15:21.212+05:30Circuit Switched Fallback (CSFB)CS domain services are the services that can be offered today in GSM-UMTS networks. Examples of such services are: voice and its supplementary services (e.g. call waiting, call forwarding), USSD, LCS, SMS, E911, LI, and even CS DUI video, etc. This rich set of CS domain features and capabilities are the result of years of standardization works in 3GPP and operators investments to their Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com2tag:blogger.com,1999:blog-6556313495977981519.post-80699824319950238682011-02-22T12:52:00.003+05:302011-02-22T13:56:48.604+05:30UE Positioning In LTEUE positioning is an access network function (e.g. GERAN, UTRAN, E-UTRAN). An access network may support one or more UE positioning methods, which may be same or different from another access network. In E-UTRAN the following UE positioning methods are supported:
Cell ID positioning method
Enhanced Cell ID based positioning method
OTDOA positioning method
NetworkVikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-26485605818764907982011-02-21T16:35:00.001+05:302011-02-21T16:36:18.387+05:30What is Evolved Packet Core ( EPC )Evolved Packet Core (EPC) is the IP-based core network defined by 3GPP in Rel-8 for use by LTE and other access technologies. The goal of EPC is to provide simplified all-IP core network architecture to efficiently give access to various services such as the ones provided in IMS.
EPC consists essentially of a Mobility Management Entity (MME), a Serving Gateway (S-GW) that interfaces with theVikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-61818526601746736272011-02-17T17:41:00.000+05:302011-02-17T17:41:07.011+05:304G Mobile Broadband Evolution: 3GPP Release-10 and Beyond
View more documents from Zahid Ghadialy.Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-65374393771838234152011-02-08T22:34:00.004+05:302011-02-08T22:57:33.620+05:30LTE – the Future of IMS
View more presentations from RADVISION Ltd..Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0tag:blogger.com,1999:blog-6556313495977981519.post-50776985832803882612011-01-25T14:56:00.003+05:302011-02-08T22:57:55.370+05:30LTE - Long Term Evolution - PresentationView more presentations from Arief Gunawan.Vikramhttp://www.blogger.com/profile/04778775507951515622noreply@blogger.com0