IEEE WoWMoM 2012 Panel

“3GPP Enhancements for Machine Type Communications Overview“

Presenter: Yenamandra S Rao

Contributors: Francesco Pica and Dilip Krishnaswamy

Qualcomm

3GPP Machine Type Communications

• Outline

– 3GPP MTC standards

– 3G PP Basic MTC architecture

– MTC Characteristics

– MTC 3GPP Release 10 features • RAN and CN Congestion/Overload protection

– MTC 3GPP Release Work Items • MTC Low Cost Model

– 3GPP New MTC Architecture • Services Capability Layer

• MTC Inter Working Function (IWF)

Machine Type Communications (MTC)

• M2M is recognized as a key segment in future cellular mobile packet data networks

• Initial 3GPP efforts have focused on the ability to differentiate MTC -type devices

– This allows the operator to selectively handle such devices in congestion/overload situations

• Low priority indicator has been added to the relevant UE-network procedures

• Overload and Congestion control is done on both core network and radio access network based on this indicator

Spec Specifications associated with or affected by MTC work

22.011 Service accessibility

22.368 Service requirements for Machine-Type Communications (MTC); Stage 1

23.008 Organization of subscriber data

23.012 Location management procedures

23.060 General Packet Radio Service (GPRS); Service description; Stage 2

23.122 Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode

23.203 Policy and charging control architecture

23.401 General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access

23.402 Architecture enhancements for non-3GPP accesses

23.888 System improvements for Machine-Type Communications (MTC)

24.008 Mobile radio interface Layer 3 specification; Core network protocols; Stage 3

24.301 Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3

24.368 Non-Access Stratum (NAS) configuration Management Object (MO)

25.331 Radio Resource Control (RRC); Protocol specification

29.002 Mobile Application Part (MAP) specification

29.018 General Packet Radio Service (GPRS); Serving GPRS Support Node (SGSN) - Visitors Location Register (VLR); Gs interface layer 3 specification

29.060 General Packet Radio Service (GPRS); GPRS Tunnelling Protocol (GTP) across the Gn and Gp interface

29.118 Mobility Management Entity (MME) - Visitor Location Register (VLR) SGs interface specification

29.274 3GPP Evolved Packet System (EPS); Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C); Stage 3

29.275 Proxy Mobile IPv6 (PMIPv6) based Mobility and Tunnelling protocols; Stage 3

29.282 Mobile IPv6 vendor specific option format and usage within 3GPP

31.102 Characteristics of the Universal Subscriber Identity Module (USIM) application

33.868 Security aspects of Machine-Type Communications

36.331 Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification

37.868 RAN Improvements for Machine-type Communications

43.868 GERAN Improvements for Machine-type Communications

44.018 Mobile radio interface layer 3 specification; Radio Resource Control (RRC) protocol

44.060 General Packet Radio Service (GPRS); Mobile Station (MS) - Base Station System (BSS) interface; Radio Link Control / Medium Access Control (RLC/MAC) protocol

45.002 Multiplexing and multiple access on the radio path

3GPP MTC Architecture

• source 3GPP (http://www.3gpp.org)

3GPP Boundary

MTC

Server GGSN / PGW / PDG

Proxy (TBD)

SGSN / MME

HLR / HSS

API MTCi

SMS-SC IP-SM-GW

Legacy SMS

IP SMS

MTCsp

Indirect model – service provider controlled

Indirect model – operator controlled Gr/S6a

Um / Uu /

LTE-Uu

RAN M2M

Application

Internal interfaces

(TBD)

Control planUser

plane

Direct model Gi/SGi

M2M Application UE

MTC User

MTCsms

3GPP Rel-10 RAN features summary

Two main features addressing network overload: • Core Network overload control

– UTRAN, E-UTRAN and GERAN

• RAN overload control – GERAN-only (EAB - Extended Access Barring)

RAN capabilities standardized in Rel-10

– Ability to configure MTC devices as (access) delay tolerant UEs

• “intended for use with MTC Devices that can delay their data transfer”

– UTRAN and E-UTRAN • ‘Delay-tolerant’ indication sent by low-priority access UEs to RAN at RRC setup • ‘Extended wait time’ (up to 30min) sent by the RAN to low-priority access UEs

– GERAN

• Core Network Overload: An Implicit reject mechanism (& reject timer up to 200 sec) is defined for the BSC to reject all devices configured for low priority access

• RAN overload: EAB, a MTC-specific broadcast mechanism for access barring

CN Overload control in (E)UTRAN: Overview

New signaling has been introduced in (E)UTRAN for CN overload control

– Core Network can indicate “overload” to RAN (not per UE), to limit Delay Tolerant traffic

– UE can indicate “delay tolerant” at Radio connection setup

– RAN can reject/release “delay tolerant” connections with “extended wait timer” (eWT)

UE RNC/NB RRC Connection Request

(new establishment cause =

Delay Tolerant Access)

Overload

New Indication:

Delay Tolerant traffic limited)

UE

RRC Connection Reject/Release

(or Signaling Connection Release)

(new Extended Wait Time)

CN/EPC

RNC/NB CN/EPC

RNC/NB CN/EPC

CN Overload control in GERAN: Overview

• CN can notify GERAN of a CN overload situation (as for (E)UTRAN)

• In GERAN, there is no explicit UE indication and RAN reject

– An implicit reject mechanism can be used by the network to reject all devices configured for low priority access.

• A mobile station configured for “low access priority” that fails to receive a

response to its access attempt but determines the BSS has enabled the implicit reject feature will abort the access procedure and start an implicit reject timer.

• While an implicit reject timer is running in a mobile station it shall consider itself as being unable to make further system access attempts

Overload

New Indication:

Delay Tolerant traffic limited)

BSS CN

GERAN RAN Overload Control

Extended Access Barring (EAB) • Extends legacy Access Control Barring (ACB), which can bar ALL UEs in a cells

• In Rel-10, UEs configured for EAB are also Delay Tolerant (and vice versa).

• In congestion, GERAN can restrict access from UEs configured for EAB only

• A UE configured for EAB shall use its allocated Access Class(s) and sub-category when evaluating the EAB information that is broadcast by the network, in order to determine if its access to the network is barred

9

Extended Access Barring (EAB)

EAB requirements/functions for GERAN Rel-10 • EAB applies to Mobile Originated (MO) calls only, except emergency calls

• The UE is configured for EAB by the HPLMN. EAB shall be applicable regardless of whether the UE is in a Home or a Visited PLMN

• If a UE that is configured for EAB is a member of an Access Class 11-15 permitted by the network, then the UE shall ignore EAB

• EAB information shall include barring information for Access Classes 0-9, plus the

differentiation of the following 3 sub-categories

– A: The EAB Authorization mask is applicable to all mobile stations configured for EAB.

– B: The EAB Authorization mask is only applicable to mobile stations configured for EAB and registered neither in their HPLMN nor in a PLMN that is equivalent to it

– C: The EAB Authorization mask is only applicable to mobile stations configured for EAB and registered neither in the PLMN listed as most preferred PLMN of the country where the UE is roaming in the operator-defined PLMN selector list on the SIM/USIM, nor in their HPLMN nor in an PLMN that is equivalent to it

AC 11: Reserved for the network operator; AC 12: Security Services (Police, Surveillance) AC 13: Public Services (Electricity,Distribution,etc); AC 14: Emergency Services AC 15: Reserved for the staff of the operator (eg. to on-site maintenance technicians)

Special Access Classes (SIM based) not subject to EAB

3GPP MTC Rel-11 features

• Few parallel Work/Study Items are ongoing in Rel-11 (still open)

– Two study Items on RAN improvements for Machine-Type Communications were started in 4Q ‘09 for GERAN and (E)UTRAN, as follow-up from Rel-10

– One large umbrella WI, System Improvements to Machine-Type Communications (SIMTC), started in May 2010, including • Many System/Core Network features and enhancements • One Work Item, common for UTRAN and EUTRAN, on RAN overload control

– One study item on Study on Provision of low-cost MTC UEs based on LTE

(FS_LC_MTC_LTE) was started in Sept. 2011

• Motivations

– Continue to enhance MTC related system/UE performance

• Specific motivations for different SI/WIs are described

3GPP Rel-11 RAN MTC enhancements

• EAB (Extended Access Barring) for (E)UTRAN – Providing RAN (and CN) overload control – Includes overload control for shared RANs

• Low cost MTC for LTE – Enabling “low cost” LTE M2M devices in the future

• Further enhancements to RAN overload control – Under study for both GERAN and (E)UTRAN – Details can be found in related 3GPP TRs:

• TR 37.868: Study on RAN Improvements for Machine-type Communications

• TR 43.868: GERAN Improvements for Machine-type Communications

3GPP Rel-11 Low Cost LTE MTC

• Study Item

– Target is Rel-12

• Proposals in 3 main areas: Radio (RF), Baseband, Operation

– Five techniques are discussed in RAN1 for cost reduction: • Reduction of maximum bandwidth

• Single receiver RF chain

• Reduction of peak rate

• Reduction of transmit power

• Half duplex operation

3GPP MTC New Architecture

13

Services

Capability

Server

Gi/SGi

Tsp

Control plane

User plane

Indirect Model

Direct Model

Hybrid Model

GGSN/

P-GW

MTC-IWF

SMS

SC/GMSC/

IWMSC

2

1

1

T4

S6m Rf/Ga

T5c

Um /

Uu /

LTE-Uu

MTC UE

Application

MME

HPLMN

VPLMN

Gi/SGi

SGSN

S-GW

UE

MSC

RAN

T5b

T5a

HSS

Tsms

Application

Server

1

Application

Server

2

IP-SM-GW

CDF/

CGF

2+

SME

3GPP Service Capability Server (SCS)

• The SCS offers capabilities for use by one or more MTC Applications. – SCS is a primarily a service platform

– SCS not defined in 3GPP

– E.g., Platform standardized by ETSI

• SCS is controlled by the operator of the HPLMN or by a MTC Service Provider

• The API between SCS and the MTC Application(s) is outside the scope of 3GPP specifications

Services

Capability

Server

Gi/SGi

Tsp

Control plane

User plane

Indirect Model

Direct Model

Hybrid Model

GGSN/

P-GW

MTC-IWF

SMS

SC/GMSC/

IWMSC

2

1

1

T4

S6m Rf/Ga

T5c

Um /

Uu /

LTE-Uu

MTC UE

Application

MME

HPLMN

VPLMN

Gi/SGi

SGSN

S-GW

UE

MSC

RAN

T5b

T5a

HSS

Tsms

Application

Server

1

Application

Server

2

IP-SM-GW

CDF/

CGF

2+

SME

3GPP MTC Interworking Function (MTC-IWF)

• MTC-IWF is controlled by HPLMN operator

• The MTC-IWF is in the HPLMN

• SCS communicates with MTC-IWF through Tsp interface

• MTC-IWF interfaces with other 3GPP entities for various MTC services – Example for device trigger

submission via SMS

Services

Capability

Server

Gi/SGi

Tsp

Control plane

User plane

Indirect Model

Direct Model

Hybrid Model

GGSN/

P-GW

MTC-IWF

SMS

SC/GMSC/

IWMSC

2

1

1

T4

S6m Rf/Ga

T5c

Um /

Uu /

LTE-Uu

MTC UE

Application

MME

HPLMN

VPLMN

Gi/SGi

SGSN

S-GW

UE

MSC

RAN

T5b

T5a

HSS

Tsms

Application

Server

1

Application

Server

2

IP-SM-GW

CDF/

CGF

2+

SME