LEKS_SF_1 Multimedia over IP Based on SIP Response codes 1xx – Provisional response 2xx – Success 3xx – Redirection 4xx – Request failure 5xx – Server failure 6xx – Global failure PSTN SIP Proxy RTP Real-time Transport Protocol SDP Session Description Protocol SIP Session Initiation Protocol TCP Transmission Control Protocol UA User Agent UAC UA Client UAS UA Server UDP User Datagram Protocol UE User Equipment URI Uniform Resource Identifier VoIP Voice over IP Media Stream Alice Bob REGISTER sip: [email protected]contact:<sip:201.32.7.1> 200 OK INVITE sip: [email protected]bob ? INVITE sip: bob@ 201.32.7.1 bob@ 201.32.7.1 ! 200 OK 200 OK ACK BYE bpis.se Location Service SIP Registrar SIP URI: sip:[email protected]SIP proxy bob@ 201.32.7.1 SIP proxy INVITE sip: [email protected]apis.se SIP URI: sip:[email protected]200 OK 200 OK 180 Ringing 180 Ringing 180 Ringing SIP Traffic Case 100 Trying 100 Trying DNS lookup Ringback Ringtone Bob answers Bob hangs up PSTN Breakout IP L2 / L1 TCP UDP AS Application Server DNS Domain Name System FQDN Fully Qualified Domain Name ISUP ISDN User Part Lx Layer x MG Media Gateway MGC Media Gateway Controller PCM Pulse Code Modulation PSTN Public Switched Telephone Network RFC Request for Comments RTCP Real-time Control Protocol SIP [RFC 3261] - Allows UAs to: register current IP address of the UA in the network set up, modify and release logical links - Can carry payload from other protocols (SDP, ISUP...) - Open to extensions (new methods, responses, headers, header values) SDP [RFC 2327, 3264] - Describes real-time multimedia sessions - Carried by e.g. SIP RTP [RFC 3550, 3267] - End-to-end transport of real-time data - Sequence numbers - Timestamps SIP User Agent Can act as: - Client (UAC), or - Server (UAS) SIP SIP SIP Any DNS SIP URI IP addr. Stores IP address [or FQDN] per subscriber authentication authorization service access implements policies routes requests Receives registrations 200.1.1.1 201.32.7.1 Audio over RTP 5000 5001 RTCP 6544 6545 Video over RTP 7654 7655 RTCP 10002 10003 [RFC 3263] sip:[email protected]Session The media stream(s), Dialogue a peer-to-peer SIP relationship between two UAs RTCP [RFC 3550] - Reports quality on RTP session port port H.248 [RFC 3015] Used by MGCF to control resources in MGW DNS SIP Proxy Server SIP Proxy Server Location Service SIP Registrar S I P RTP RTCP Real-time app. SIP URI: sip:[email protected]SIP ISUP RTP PCM H.248 SIP MGC MG Control plane (Signalling) User plane (Transmission) Any Eg. VoIP
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RTP Real-time Transport Protocol SDP Session Description Protocol SIP Session Initiation Protocol TCP Transmission Control Protocol UA User Agent UAC UA Client UAS UA Server UDP User Datagram Protocol UE User Equipment URI Uniform Resource Identifier VoIP Voice over IP
AS Application Server DNS Domain Name System FQDN Fully Qualified Domain Name ISUP ISDN User Part Lx Layer x MG Media Gateway MGC Media Gateway Controller PCM Pulse Code Modulation PSTN Public Switched Telephone Network RFC Request for Comments RTCP Real-time Control Protocol
SIP [RFC 3261]
- Allows UAs to:
register current IP address of the UA in the network
set up, modify and release logical links
- Can carry payload from other protocols (SDP, ISUP...)
- Open to extensions (new methods, responses, headers,
PCC Policy and Charging Control PCEF Policy and Charging Enforcement Function PCRF Policy and Charging Rules Function PGW Packet Data Network Gateway PDN Packet Data Network QoS Quality of Service RTSP Real Time Streaming Protocol SDF Service Data Flow SGSN Serving GPRS Support Node SGW Serving Gateway SIP Session Initiation Protocol SPR Subscriiption Profile Repository TDF Traffic Detection Function UDR User Data Repository VoIP Voice over IP
AF AF
Node that uses PCC, e.g.:
• Media Server or CSCF
For Operator Controlled Services
GW PCEF Audio + Video over IP
One IP-CAN Session
Two IP-CAN Bearers
Three SDFs: Signaling, Audio, Video)
ADC Application detection and Control AF Application Function APN Access Point Name CSCF Call Session Control Function DPI Deep Packet Inspection eNB Evolved Node B EPS Evolved Packet System E-UTRAN Evolved UTRAN GGSN Gateway GPRS Support Node GW Gateway IP-CAN IP Connectivity Access Network LTE Long Term Evolution MMtel Multimedia Telephony OCS Online Charging System OFCS Offline Charging System
SIP
Default EPS Bearer
eNB PGW SGW
EPS
IP-CAN
Bearers
”Session Based Service”
PCEF
PDN 2: Internet
Video Streaming
Email
File Transfer
Example:
• One IP-CAN Bearer
• 3 Service Data Flows
SDFs identified e.g. with DPI
SDF
Dedicated EPS Bearer
IP-CAN
Session
PCRF SPR/ UDR
TDF IP-TV
MMtel
APN X
APN Y
Gx Rx
OFCS OCS
IP-CAN Problems Ro
Gy Gz
MME
HSS
1
1 1
1
1 2
1
1 3
1
1 4 1
1 5
HNW
VNW
1
1 6
1
1 8
1
1 9
KPI: Session setup success rate
RRC establishment S1 link establishment ERAB establishment
SR Success Rate QCI Quality Cllass Indicator IP Internet Protocol QoS Quality of Service PDN Packet Data Network IMS Internet Multimedia Subsystem RRU Radio Remote Unit UP User Plane
(cause= Req. Accept) S1AP DL NAS Transport (Detach
Request)
S1AP UL NAS Transport (Detach
Accept)
UE ctx Release Req./Resp. DIAMETER Notification
Req./Answer
X CP IP#
UP IP# CP IP#
UP IP# X X
IP # X
+ ppt ”Failure Cases…”
LEKS_SF_15
RRC Connection Problems CCCH SRB 0 RLC-SAP TM
DCCH SRB 1 RLC-SAP AM
BCCH : BCH : PBCH
MIB (DL bandwidth/# RB)
RS RSRP
RSRQ
PSS (0, 1, 2) 5 ms loop that gives slot synch
To detect the 10 ms frame start SSS (0 .. 167)
PDCCH CRC : for me?
PDSCH : DL-SCH : BCCH
SIBs (tell UE how to behave)
PRACH : RACH
preamble
PCFICH
Indicates the size of the DCI
(1, 2, 3, or 4 OFDM symbols)
PDCCH
DCI UL Assignment: (UE ID,
PRBs, MCS, HARQ id, TPC)
PUSCH : UL:SCH : CCCH
RRC Connection Request (cause …)
CRC
24
TrBlk
RNTI
data
Input data vector for
a CRC, masked with
RNTI
If ERR ~= 0 then either an error has occurred or
the input CRC has been masked.
MAC-IDs
UL : RA_RNTI
DL : P-RNTI, SI-RNTI
UL/DL : C-RNTI
PCFICH
PDCCH
PDSCH : DL : SCH : CCCH
RRC Connection Response
(UE ID, DCCH, …)
RACH: MAC Rand. Acc. Preamble
(RA-RNTI, preamble index)
Error Not sent/Not received
UL-SCH/CCH: RRC Con. Req (temp
C-RNTI, NAS UE ID=IMSI or TMSI
1
2 Error RRC Con. Reject
( cause=?, wait time)
RRC Security Mode Command
3 Error RRC Security Mode
Failure (cause ?)
RRC Con. Reconfig.
4 Error RRC Con. Re-est. Req.
(cause =”reconfig. failure”
RRC Con. Re-establ. (new
SRB 1, new security ctx).
RRC Con. Re-establ. Compl. OK!
Error RRC Con. Re-
establ. Reject (cause ?)
5
or ...
Failure!
1
2
3
4
5
Error on Uu: interference on DL-SCH, coverage? High TA? Solution:
partial freq. Reuse!
eNB CPU overload?
Typically cell congested, no radio resources. ? =
• ”reconfig. Failure”
• ”HO failure”
• ”other reason” - wait time second before new request (1 .. 16)
Typically due to problem in handset during ciph/integr. Procedure….
Sent instead of ”RRC Con. Reconfig. Complete”. eNB must take
decision what to do…
RLC AM used for RRC sign. but ACK never received (not sent or
interference?). If repeated eNB drops the con. And release UE…
If S1AP cause = ”failure in Uu procedure” or ”release due to EUTRAN”
possible caused by AM errordue to interference or problem in UE
power control…
freq
(power)
LEKS_SF_16
SCH Shared Channell QoS Quality of Service TTI Transmission Time Interval VoIP Voice over IP RRC Radio Resource Control PRB Physical Resource Block MCS Modulation and Coding Scheme RI Rank Indicator PMI Precoding Matrix Indicator MIMO Multiple Input Multiple Output PAPR Peak to Average Power
MAC-Scheduler Purpose:
• Efficient SCH(Data) Resources
Assignments
Consideration
• Traffic Volume, QoS (Buffer
Status, Priority…)
• Channel Condition
Scheduling Interval
• Dynamic Scheduling by MAC :
One TTI (1ms : One Sub-
frame)
• Semi-Persistent for VoIP :
Multiple TTIs by RRC
Resource Assignment :
• PRBs & MCS
MIMO
• RI and PMI
Freq.
Time.
DL OFDMA:
High Throughput
High PAPR
UL SC-FDMA:
Fair Throughput
Low PAPR saves battery…
RE Mapping Cell Specific
Scrambling
Layer
Mapping
(symbols
mapped on
1,2,3,4
layers)
Modulation
(QPSK,
xQAM)
Precoding
(mapping to
1, 2or
4antenna
ports) RE Mapping
OFDM
(IFFT)
OFDM
(IFFT) Code word, qo
Pseudo
Random bit
sequence
Depends on selected tx mode:
•Single antenna tx
• tx diversity
• spatial multiplexing (MIMO)
• beamforming
X
i
.
.
.
.
Y
i
.
.
.
.
Code
word, q1
(if MIMO)
1 modulation
Symbol -> RE
antenna
ports
.
.
.
CRC 24 Code Block
Segmentati
on
FEC
Turbo
Coding
R = 1/3 To detect
bit errors If input >
6144 bits Bit error
correction
Sub block
Interleaving
Rate
Matching
Code Block
Concatenati
on
To achieve
high throuput
and error
correct
coding by
HARQ
Add
segmentet
blocks...
1 TB
PDU
S
P1
P2
”Code Word”
MAC PHY
Output
Assignment
(DL)
Grant (UL)
Scheduler
Data related inputs
•HARQ retransmissions
•Data buffer (DL)
User related inputs
•UE capabilities
•UE measurement gaps
•Sync status
QoS
translation
•UE prioritization
•Resource
Allocation
•PDCCH resources
•Buffer estimation
(UL)
•RB and symbols
•DL Power
Power Control
CQI (DL)
PMI(DL)
RI(DL)
MCS (DL)
QCI table
•Priorities
•LCGs
SINR(UL)
RRC Connection
Request (UL)
• UL interference based on i.e eNB sharing of load over X2 with max
20ms
• 3G quality can be measured DL/UL with ded. Ch’s. LTE user are
distributed in time x freq. Test mobiles can never measure UL quality.
• Satisfy latency and packet error loss characteristics of each QCI class
• Satisfy Guaranteed Bit Rate (GBR), Minimum Bit Rate (MBR)
• Enforce downlink maximum bit rate for sum of downlink bearers
• new users are admitted only when QoS requirements of existing and newly added
users/bearers can be met.
• perform frequency selective and frequency diverse scheduling (localized and
distributed virtual resource blocks) depending upon channel conditions,
QoS requirements etc.
• Adapt TB size, MIMO and rank depending on CQI, PMI and RI from UEs plus data buffers
• Higher priority to HARQ re-tx versus new tx…
RSRQ = NRB x RSRP
RSSI
LEKS_SF_17
Radio Quality Downlink
UL Scheduling Req.
• Power Headroom
• Buffer Status Reporting (long and Short)
The three most important tasks in LTE prelaunch radio parameter planning are:
1 Physical Cell Identity (PCI) allocation
2 Physical Random Access Channel (PRACH) parameter planning, and
3 Uplink reference signal (RS) sequence planning
During/after launch are:
4: UL Power control
5: Handover thresholds
6: Paging (MME/eNB paging capacity)
7: Control Channel planning
Also SI-time-to-release and DRX-cycle should be configured…
MIMO
MIMO
PCI
PCI
PCI
PR
AC
H
Attach Request
Connected Mode UE UL RS
Handover thresholds
UL PC
MME P
a
g
i
n
g
UL Path Loss
DL Path Loss
Uplink Budget, 64
kbps, 2 RB’s, 3-
sector macro-cell
Downlink Budget,
1 Mbps, Antenna
Diversity, 10 MHz,
46 dBm ”When needed”
~ 100 Hz
UMTS CPICH
GSM RSSI
dB/dBm
t
RSRQ
RSRP
RSRQ bad while RSRP
stable = increasing DL
interference
Both RSRQ and RSRP bad
= path loss…
t1
t1 + t
Timing Advance, TA
To synch tx/rx of UL radio
(UE/eNB) in time domain
eNB sends TA value in RACH responce.
TA = 0 .. 1287 = UE sent RACH at max 200 km
distance = cell range of 100 km.
TA = 0,52 μs = 156 m
MAC timing advance command values between 0
and 63.
Using the 64 index values, a distance of 64 x
156m
= 10 km so ± 5km at 3600km/h.
PRACH Planning
839 preamble sequences available
Paging (MME/eNB paging capacity)
The process of TA dimensioning contains two main tasks:
• TA dimensioning for the MME
• TA dimensioning for the RBS
Number of ZC sequences required per cell, for a
given random access radius. A cell requires five
ZC sequences per cell for up to 7.3km radius,
which is typically sufficient for urban and
suburban macro cells. This results in sequence
reuse factor of at least 839/5 ≈ 167 cells, hence
allows for easy planning process.
Paging Failures
• defective handsets;
• insufficient coverage;
• wrong settings for broadcast cell (re)selection parameters like S0
criteria.
LEKS_SF_18
Performance
• ”Call Drops” due to Uu
MME
Opt: RRC Con. Release
(cause=”unspecified”) UE ctx Rel. Request
(”failure due to EUTRAN”)
UE ctx Rel. Command
(cause=”normal release”)
UE ctx Rel. Complete
May not be seen as dropped from for the user… since UE
moves in/out from IDLE. Takes 1 – 2 seconds to setup
RRC…
Makes sence to distinguis between subscriber level (QoE)