MLINARSKY Considerations for PS LTE Architecture 09 29 2011

8/11/2019 MLINARSKY Considerations for PS LTE Architecture 09 29 2011

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NPSTC is a federation of organizations whose mission is to improve

public safety communications and interoperability through collaborative leadership.

Authors:

Fanny Mlinarsky, octoScope, [email protected]

Dr. Ming Lai, Telcordia, [email protected]

Jose Graziani, octoScope,[email protected]

29-Sep-11


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NPSTC is a federation of organizations whose mission is to improve public safety

communications and interoperability through collaborative leadership.

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Project summary

Handset and network architecture for a PS LTE MC Voice service

IMS-based LTE voice service

Talkaround mode based on 802.11s mesh architecture with patent-pending ivMesh

technology to solve some of the issues with mobile mesh

IMS-EPC testbed for testing the IMS based handset client

PTT over partner LMR radio

Connection Manager

MC = mission critical

IMS = IP multimedia subsystem

PTT = push to talk

LTE = long term evolutions

PS = public safety

EPC = evolved packet core

LMR = land mobile radio


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Push to talk (< 500 ms connection time)

Low latency (< 100 ms)

Talkaround mode of operation

Priority access with or without pre-emption

Guaranteed voice message delivery

Security with encryption

Simultaneous voice and data (e.g. seeing

location of callers when talking)

VoIP recording

Voice service roaming and interworking withprivate public safety networks and commercial

cellular networks

Talkaround meshLTE infrastructure


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IMS based LTE network architecture to support voice,

data, video, PTT, QoS

Interworking function to interconnect legacy handsets,

including P25 and analog radios, to the PS LTE network

Seamless mobility among islands of PS LTE coverageinterconnected via commercial 2G/3G and LTE networks

Talkaround mode of operation using patent-pendingivMeshTMtechnology (802.11s with layer 2 distributed

voice protocol)

Call manager function in the handset to switch operating

modes

Infrastructure PS LTE

Infrastructure 2G/3G and LTE via commercial cellular radio

Talkaround QoS = quality of serviceivMesh = isochronous voice mesh

Handset to incorporate

LTE, 2G/3G and Wi-Firadios, based on off-the-

shelf hardware

Interoperability with legacy

radios ensured by the

infrastructure Interworkingfunction


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Open source platform, such as Android with off the shelf radio modules

Patent-pending ivMeshTMlayer 2 voice technology seamlessly rides on the heart beat of an

802.11s network

Optional VHF front end for longer range White Spaces [5] or 900 MHz band(Note: We

would prefer to use the licensed 700 MHz band but FCC disallows transmissions other than

LTE Release 8 in this band, per FCC Order 10-79 issued May 12, 2010)ivMesh = isochronous voice mesh

PoC = PTT over cellular

VHF = very high frequency

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The PS community needs a certification standard for PS handsets

similar to GCF and PTCRB

GCF is responsible for LTE conformance testing with the

focus on European operators; PTCRB provides certification

for North American operators

PS certification has unique certification requirements, for example:

PTT-specific certification with the focus on priority and

preemption features infrastructure and talkaround modes

Seamless roaming and VCC among islands of PS LTE

networks and commercial 2G/3G/LTE networks

PS security related certification

Call management and VCC between infrastructure and

talkaround modes, OTA provisioning and other such

operational functionality

Coordinate with PSCR UE Testing Study group

PTCRB = PCS Type Certification Review Board

PCS = Personal Communications System,

GCF = Global Certification Forum

VCC = voice call continuity

PSCR = public safety communications research

UE = user equipment

www.globalcertificationforum.org

www.ptcrb.com

PS IMS-EPC-LTE testbed

to be developed for this

project may be useful to the

PSCR community


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Issue with conventional 802.11s network

ivMesh solution

The ongoing process of self-healing and self-

forming of a mesh with mobile mesh nodescould result in bursts of dropped voice packets

and thus degrade voice quality.

Collaborative packet recovery whereby each

node can request from other nodes voicepackets missing from its RX queue

The ongoing process of self-healing and self-forming of a mesh with mobile mesh nodescould result in excessive traffic used by

conventional routing algorithms to rebuildrouting tables following each topology change

Zero-noise routing protocol whereby pathdiscovery information is inserted into voicepackets thus eliminating special path discovery

traffic and freeing the airlink bandwidth for voicepacket recovery

Unpredictable and variable delays inherent to

the mesh topology could degrade voice quality.

Protocol layer reduction whereby voice-specific

layer 2 functionality can expediently forwardpackets through the mesh at the highest priority

and quickly recover routing tables after self-healing; use of receive buffers for elimination of

itter that results from irregular delays through

mesh network


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Voice packet stream is a series of

short packets (100-200 usec,

depending on the CODEC)separated by gaps on the order of

20 msec. To optimize voicequality, packets need to be

recovered at the receiver at

regular intervals (i.e.isochronously).

ITU has defined voice quality

standards with R-Factor being

commonly used as a VoIP metric

Delay,jitter (packet to

packet delay variation

through the network) and

packet loss result indegraded voice quality.


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Parameter Abbr. Unit Default Value Permitted Range

Send Loudness Rating SLR dB +8 0 +18

Receive Loudness Rating RLR dB +2 -5 +14

Sidetone Masking Rating STMR dB 15 10 20

Listener Sidetone Rating LSTR dB 18 13 23

D-Value of Telephone, Send Side Ds - 3 -3 +3

D-Value of Telephone Receive Side Dr - 3 -3 +3

Talker Echo Loudness Rating TELR dB 65 5 65

Weighted Echo Path Loss WEPL dB 110 5 ... 110

Mean one-way Delay of the Echo Path T ms 0 0 500

Round-Trip Delay in a 4-wire Loop Tr ms 0 0 1000

Absolute Delay in echo-free Connections Ta ms 0 0 500

Number of Quantization Distortion Units qdu - 1 1 14

Equipment Impairment Factor Ie - 0 0 40

Packet-loss Robustness Factor Bpl - 1 1 40

Random Packet-loss Probability Ppl % 0 0 20

Circuit Noise referred to 0 dBr-point Nc dBmOp -70 -80 -40

Noise Floor at the Receive Side Nfor dBmp -64 -

Room Noise at the Send Side Ps dB(A) 35 35 85

Room Noise at the Receive Side Pr dB(A) 35 35 85

Advantage Factor A - 0 0 20


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MOS (mean opinion score) uses a wide range of human subjects to provide a

subjective quality score (ITU-T P.800); E-Model computes Rating Factor or

R-Factor as a function of delay, packet loss and other variables (ITU-T G.107)

MOS

R

Excellent 5

Good 4

Fair 3

Poor 2

Bad 10 20 40 60 80 100


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3GPP proposal for a study on Proximity-based Services at 3GPP SA1

ftp://ftp.3gpp.org/TSG_SA/TSG_SA/TSGS_53/Docs/SP-110638.zip

Direct UE to UE mode of operation

Work appears to have started more than 10 years ago; championed by Qualcomm

Not clear how this would work in an FDD LTE network with radios having UL/DL at

different frequencies and thus being unable to communicate with one another;

Will likely require TDD

Not clear whether this will involve 2 devices or a mesh of devices

Justification: Proximity-based applications and services represent a recent and

enormous socio-technological trend. The principle of these applications is to discover

instances of the applications running in devices that are within proximity of each other,

and ultimately also exchange application-related data. In parallel, there is interest inproximity-based discovery and communications in the public safety community

FDD = frequency division duplexing

TDD = time division duplexing

UE = user equipment

UL = uplink

DL = downlink


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PTT over ivMesh for talkaround

Prototype ivMesh layer 2 based voice solution for talkaround mode

Integrate PTT over ivMesh

PTT over IMS

Prototype PTT software over IMS and test it against the IMS/EPC testbed based on

FOKUS [6] IMS-EPC testbed

Develop and test key components of Connection Manager

Integrate PTT/ivMesh, PTT/IMS, PTT/LMR and Connection Manager client

software into a partner LMR radio and test operation using actual radios


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Open 802.11s

http://open80211s.org/

Integrated in Linux kernel as of 2.6.26

Atheros support for 5xxx chips in 2.6.29 (legacy 11g/a)

Atheros support for 9xxx (11g/a/n) BATMAN support added in 2.6.33

www.open-mesh.org

Ad-hoc routing protocols

http://en.wikipedia.org/wiki/Ad_hoc_routing_protocol_list

IETF Mobile Ad-hoc Networks (MANET) http://datatracker.ietf.org/wg/manet/charter/


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HWMP (802.11s default)

Based on AODV routing (RFC 3561)

Used in MANETs

802.11s allows for alternative and flexible implementations of path selection protocols and metrics.

RA-OLSR used to be an alternative in the earlier 802.11s drafts

Babel

Based on OLSR

Distance-vector routing protocol (RFC 6126); loop avoiding

Open source: http://www.pps.jussieu.fr/~jch/software/babel/; stand-alone application - not part

of the Linux kernel; not limited to wireless networks

BATMAN Advanced

Layer 2

Open source: http://www.open-mesh.org/HWMP = hybrid wireless mesh protocol

AODV = Ad hoc On-Demand Distance Vector

MANET = mobile ad hoc networking

BATMAN = better approach to mobile ad-hoc networking

OLSR = optimized link state routing

RA-OLSR = radio aware OLSR


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Maximize attenuators to force auto-re-routing of traffic flow to test self-healing

Fixed attenuators to set traffic

flow via one branch or another

to test self configuration

1

Traffic

analyzer

Traffic

generator

Fail-over conditions

Emulate failure conditions by setting

programmable attenuators to causetraffic flow reconfiguration.

All mesh nodes are in

RF isolation boxes

Test the operation of VoIP over 802.11s by constructing this mesh topology. Each mesh node is a PC running the

prototype software. Simulate the motion of the mesh nodes by varying programmable attenuators under software

control. Verify and refine the self-healing capabilities, which are critical to a mobile mesh network.


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In September of 2010 the FCC has reaffirmed its decision to allow

unlicensed communications in the White Spaces UHF band that

neighbors the PS 700 MHz band

If 700 MHz 802.11 RF front end chipset is developed for the White

Spaces market, it could be used to extend the range of the ivMesh

talkaround communications. Otherwise unlicensed 800/900 MHz

band could be used for ivMesh. [5]


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NPRM in May 2004 http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-113A1.pdf

November 4, 2008 FCC approved Report & Order 08-260, allowing

unlicensed use of TV band spectrum

http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-01-260A1.pdf

February 17, 2009, the FCC released the final rules for Unlicensed

Operation in the TV Broadcast Bands http://edocket.access.gpo.gov/2009/pdf/E9-3279.pdf

Sep 23, 2010 The FCC reaffirmed a 2008 decision to open the

broadcast airwaves

NPRM = Notice of Proposed Rule Making


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Ofcom (UK) is in the process of making this Digital Dividend band

available https://mentor.ieee.org/802.18/dcn/09/18-09-0059-00-0000-ofcom-update-on-the-digital-dividend.ppt

http://stakeholders.ofcom.org.uk/consultations/geolocation/summary

ECC of CEPT in Europe has published a report on White Spaces inJan 2011 http://www.erodocdb.dk/Docs/doc98/official/pdf/ECCREP159.PDF

China TV band regulations expected in 2015

ECC = Electronic Communications Committee

CEPT = European Conference on Postal and Telecommunications


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DB 3

DB 2DB 1

Mode II Device

Mode I Device

GPS Satellite

IETF PAWS

IETF = internet engineering task force

PAWS = protocol to access white space

Geolocation

Available channels

Spectrum access is database-driven. Database is designed to protect licensed

TV transmitters from interference by unlicensed White Spaces devices.


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Channel # Frequency Band

5-12 174-230 MHz VHF

21-60 470-790 MHzUHF

61-69 790-862 MHz

White Spaces

Channel # Frequency Band

2-4 54-72 MHz

VHF5-6 76-88 MHz

7-13 174-216 MHz

14-20 470-512 MHz**

UHF21-51* 512-692 MHz

FixedTVBDs

only

*Channel 37 (608-614 MHz) is reserved for radio astronomy

**Shared with public safety

Transition from NTSC

to ATSC (analog to

digital TV) June 12,

2009 freed upchannels 52-69 (above

692 MHz)

White Spaces

US FCC

Europe ECC


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0 100 200 300 400 500 600 700 800 900

US (FCC) White Spaces

54-72, 76-88, 174-216, 470-692 MHz

European (ECC) White Spaces (470-790 MHz)

MHzLow 700 MHz band

High 700 MHz band including

Band 14 PSBB and PSNB

US Licensed

UHF Spectrum

PSBB = public safety broadband

BSNB = public safety narrow band

700 MHz PS RF front end could serve PS band

along with the international White Spacesband. Commercial chipsets may be coming to

support this band for White Spaces.


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26www.octoscope.com

IEEE 802.11 (Wi-Fi) operates in theISM-2400 and ISM-5800 bands and in the

5800 UNII band; recently standardized for3650-3700 contention band

IEEE 802.16 (WiMAX) operates in theUNII/ISM band and in the 3500-3700 MHz

contention band

Cordless phones

ISM-900 traditionally used for consumerdevices such as cordless phones, garage

openers and baby monitors, now also usedon smart meters

proprietary Standards-based

UWB based WiMedia is a short-rangenetwork operating in the noise floor of other

services


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Frequency range Bandwidth Band Notes

433.05 434.79 MHz 1.74 MHz ISM Europe

420450 MHz 30 MHz Amateur US

868-870 MHz 2 MHz ISM Europe

902928 MHz 26 MHz ISM-900 Region 2

2.42.5 GHz 100 MHz ISM-2400

International

allocations

(see slides 7,

8 for details)

5.155.35 GHz 200 MHz UNII-1,2

5.475.725 GHz 9RR K0S TUNNV9 4W3G

5.7255.875 GHz 150 MHzISM-5800

UNII-3

2424.25 GHz 250 MHz ISM T>D #O%)+4

57-64 GHz

59-66 GHz7 GHz ISM

US

#O%)+4

Emerging 802.11ad

802.15.3c, ECMA-387

WirelessHD

802.11b/g/n, Bluetooth

802.15.4 (Bluetooth, ZigBee),

cordless phones

802.11a/n, cordless phones

Smart meters, remote

control, baby monitors,

cordless phones

Medical devices

Remote control

5A4%(?&7D (-?.O'(-8 T> &-'

@&-&'&J 5O73%&.(&D N7%&4.

RFID and other unlicensed

services

#O%)+4&- &-&.)8 )2

3Q4 N>KVXFF Y&-'Possible VHF bands for ivMesh


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Fraunhofer Institute FOKUS, Germany

www.FOKUS.fraunhofer.de/go/ngni

www.FUSECO-Playground.org

www.OpenEPC.net

Open source EPC and IMS over LTE


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AAA

Authentication, Authorization, and Accounting

BSI Bridging Systems Interface

CMAS Commercial Mobile Alert System

EPC

Evolved Packet Core

HSS Home Subscriber Server

IMS IP Multimedia Subsystem

ISSI

Inter-RF Sub-System Interface

IWK Interworking

LI

Lawful InterceptionLTE

Long Term Evolution

MAC Medium Access Control

MC Mission Critical

MPS

Multimedia Priority Service

MS Media Server

OMA-DM Open Mobile Alliance Device Management

PCRF

Policy Charging and Rules Function

POC

Push to talk Over CellularPS Presence Server

PSAP

Public Safety Answering Point

PTT Push To Talk

VR VoIP Recording

XDMS

XML Document Management Server

Documents

MLINARSKY Considerations for PS LTE Architecture 09 29 2011