Mobile Communications: Difference between revisions
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==LTE Architecture== | ==LTE Architecture== | ||
LTE Long Term Evolution. | |||
===UE=== | ===UE=== | ||
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User Equipment. | User Equipment. | ||
===SAE=== | |||
{{External|https://en.wikipedia.org/wiki/System_Architecture_Evolution}} | |||
System Architecture Evolution (SAE) is the core network architecture of 3GPP LTE wireless communication standard. | System Architecture Evolution (SAE) is the core network architecture of 3GPP's LTE wireless communication standard. | ||
===EPC=== | ====EPC==== | ||
Evolved packet core is the main component of the [[#SAE|SAE]]. | Evolved packet core is the main component of the [[#SAE|SAE]]. | ||
===MME=== | ====S1AP==== | ||
The S1 Application Protocol (S1AP) describes the communication between [[#UE|UE]] and [[#EPC|EPC]]. | |||
====MME==== | |||
Mobility Management Entity is the main signaling node in the [[#EPC|EPC]], responsible for initiating paging and authentication of the mobile device. MME retains location information at the tracking area level for each user and then selects the appropriate gateway during the initial registration process. MME connects to the evolved node b (eNB) through the S1-MME interface and connects to S-GW through S11 interface. Multiple MMEs can be grouped together in a pool to meet increasing signaling load in the network. MME is also the main control node in the LTE access network. It has the following functions: | '''Mobility Management Entity''' is the main signaling node in the [[#EPC|EPC]], responsible for initiating paging and authentication of the mobile device. MME retains location information at the tracking area level for each user and then selects the appropriate gateway during the initial registration process. MME connects to the evolved node b (eNB) through the S1-MME interface and connects to S-GW through S11 interface. Multiple MMEs can be grouped together in a pool to meet increasing signaling load in the network. MME is also the main control node in the LTE access network. It has the following functions: | ||
* Network Access Control: MME manages authentication and authorization for the UE. It also facilitates UE access to the network to gain IP connectivity. | * Network Access Control: MME manages authentication and authorization for the UE. It also facilitates UE access to the network to gain IP connectivity. | ||
* Radio Resource Management: MME works with the HSS and the RAN to decide the appropriate radio resource management strategy (RRM) that can be UE-specific. | * Radio Resource Management: MME works with the HSS and the RAN to decide the appropriate radio resource management strategy (RRM) that can be UE-specific. | ||
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* Roaming Management. | * Roaming Management. | ||
* UE Reachability. MME manages communication with the UE and HSS to provide UE reachability and activity-related information. | * UE Reachability. MME manages communication with the UE and HSS to provide UE reachability and activity-related information. | ||
* Tracking Area Management: | * Tracking Area Management: allocates and reallocates a tracking area identity list to the UE. | ||
* Lawful Intercept | |||
* Load Balancing between S-GWs: Directs UEs entering an S-GW pool area to an appropriate S-GW. This achieves load balancing between S-GWs. | |||
=====Network Attach Procedure===== | |||
http://www.lteandbeyond.com/2012/01/lte-attach-procedure.html | |||
====SGW==== | |||
'''Serving Gateway''' | |||
====PGW==== | |||
'''PDN Gateway''' | |||
====HSS==== | |||
'''Home Subscriber Server''' is a central database that contains user-related and subscription-related information. Functions: | |||
* mobility management | |||
* call and session establishment support | |||
* user authentication and access authorization. | |||
==Radio Resource Control RRC== | |||
The Radio Resource Control (RRC) protocol is used in LTE on the Air interface. This is a layer that exists between UE and eNB, and exists at the IP level. | |||
Latest revision as of 18:05, 6 July 2018
Internal
Concepts and Terms
IMSI
IMSI International Mobile Subscriber Identity is an unique number, usually fifteen digits, associated with Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UTMS) network mobile phone users, identifying a GSM subscriber. The number has two parts: first six digits (North American standard) identify the network operator in a specific country with whom the subscriber holds an account. The second part is allocated by the network operator to uniquely identify a subscriber.
LTE Architecture
LTE Long Term Evolution.
UE
User Equipment.
SAE
System Architecture Evolution (SAE) is the core network architecture of 3GPP's LTE wireless communication standard.
EPC
Evolved packet core is the main component of the SAE.
S1AP
The S1 Application Protocol (S1AP) describes the communication between UE and EPC.
MME
Mobility Management Entity is the main signaling node in the EPC, responsible for initiating paging and authentication of the mobile device. MME retains location information at the tracking area level for each user and then selects the appropriate gateway during the initial registration process. MME connects to the evolved node b (eNB) through the S1-MME interface and connects to S-GW through S11 interface. Multiple MMEs can be grouped together in a pool to meet increasing signaling load in the network. MME is also the main control node in the LTE access network. It has the following functions:
- Network Access Control: MME manages authentication and authorization for the UE. It also facilitates UE access to the network to gain IP connectivity.
- Radio Resource Management: MME works with the HSS and the RAN to decide the appropriate radio resource management strategy (RRM) that can be UE-specific.
- Mobility Management: provide seamless inter-working.
- Roaming Management.
- UE Reachability. MME manages communication with the UE and HSS to provide UE reachability and activity-related information.
- Tracking Area Management: allocates and reallocates a tracking area identity list to the UE.
- Lawful Intercept
- Load Balancing between S-GWs: Directs UEs entering an S-GW pool area to an appropriate S-GW. This achieves load balancing between S-GWs.
Network Attach Procedure
http://www.lteandbeyond.com/2012/01/lte-attach-procedure.html
SGW
Serving Gateway
PGW
PDN Gateway
HSS
Home Subscriber Server is a central database that contains user-related and subscription-related information. Functions:
- mobility management
- call and session establishment support
- user authentication and access authorization.
Radio Resource Control RRC
The Radio Resource Control (RRC) protocol is used in LTE on the Air interface. This is a layer that exists between UE and eNB, and exists at the IP level.