Master’s Thesis Oral Defense

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Outline
2019/10/30 1
• Introduction
• Related Work
• Proposed Method
– System Architecture
– GTP-Support OpenFlow Service
– Low-Latency Service
– Flow Redirecting Service
• Experiments
• Conclusion

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Outline
2019/10/30 2
• Introduction
• Related Work
• Proposed Method
• Experiments
• Conclusion

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Introduction(1/5)
2019/10/30 3
• From 4th generation to 5th generation mobile
networks
– From closed system to open source platform.
– From dedicated entities/protocols/hardware to
Service Based Architecture (SBA).
– Fast and elastic deployment.
– Key roles-NFV and SDN.

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Introduction(2/5)
2019/10/30 4

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Introduction(3/5)
2019/10/30 5
• Network Function Virtualization (NFV) is to
transit individual network services that require
dedicated hardware to function virtual
machines.

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Introduction(4/5)
2019/10/30 6
• Software Define Networking (SDN) is a
physical separation of network control plane
from data plane and centralized controls
several devices.

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Introduction(5/5)
2019/10/30 7
• 5G three application scenarios

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Outline
2019/10/30 8
• Introduction
• Related Work
• Proposed Method
• Experiments
• Conclusion

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Related Work(1/12)
2019/10/30 9
• GTP in LTE
• Use Open Source Software (OSS)
– OpenAirInterface
– OpenStack
– OpenDaylight
• Other research architectures

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Related Work(2/12)
2019/10/30 10
• General Packet Radio Service (GPRS)
Tunneling Protocol (GTP) is a group of IP-
based communications protocols.
• GTP used to carry general packet radio service
(GPRS) within GSM (2G), UMTS (3G) and
LTE (4G) networks.

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Related Work(3/12)
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• Three GTP categories
– GTP-C: For control PDP (Packet Data Protocol)
Context, reachable validation and tunnel creation,
deletion and update.
– GTP-U: For multiple tunnels carry UE data to
transport.
– GTP’: For operators to charge payment.

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Related Work(5/12)
2019/10/30 13
• Use Open Source Software (OSS)
– OpenAirInterface
– OpenStack
– OpenDaylight

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Related Work(6/12)
2019/10/30 14
• OSS-OpenAirInterface
– EURECOM has created the OpenAirInterface
(OAI) Software Alliance (OSA).
– An open-source ecosystem for the core (EPC) and
access-network (EUTRAN) protocols of 3GPP
cellular systems.

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Related Work(7/12)
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• OSS-OpenStack

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Related Work(8/12)
2019/10/30 16
• OSS-OpenDaylight
– The Linux Foundation is responsible for managing
open source projects.
– OpenDaylight is a multi-protocol controller
framework based on SDN development.
– Support OpenFlow to control switches.

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Related Work(9/12)
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• Other research architectures
– Removed GTP Architecture
– vEPC
– Low-Latency-Multi-access Edge Computing (LL-
MEC)

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Related Work(10/12)
2019/10/30 18
• Removed GTP Architecture

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Related Work(11/12)
2019/10/30 19
• vEPC-Proposed by ETSI

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Related Work(12/12)
2019/10/30 20
• LL-MEC -Proposed by EURECOM

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Outline
2019/10/30 21
• Introduction
• Related Work
• Proposed Method
– System Architecture
– GTP-Support OpenFlow Service
– Low-Latency Service
– Flow Redirecting Service
• Experiments
• Conclusion

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Proposed Method
2019/10/30 22
• System Architecture
• GTP-Support OpenFlow Service
• Low-Latency Service
• Flow Redirecting Service

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Application Layer
Control Layer
Infrastructure Layer

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Proposed Method
2019/10/30 25
• System Architecture
• GTP-Support OpenFlow Service
• Low-Latency Service
• Flow Redirecting Service

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GTP-Support OpenFlow Service(1/4)
2019/10/30 26
• Let SDN controller handle UE’s traffic after UE
attach, including Uplink and Downlink.
• Controller can do more action in OpenFlow spec.
– Modify header,drop,QoS,…etc.

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GTP-Support OpenFlow Service(2/4)
2019/10/30 27

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GTP-Support OpenFlow Service(3/4)
2019/10/30 28
• Uplink
• Downlink

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GTP-Support OpenFlow Service(4/4)
2019/10/30 29
• Uplink
• Downlink

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Proposed Method
2019/10/30 30
• System Architecture
• GTP-Support OpenFlow Service
• Low-Latency Service
• Flow Redirecting Service

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Low Latency Service
2019/10/30 31
• GTP Decapsulation and Encapsulation
• Floating IP Architecture

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Low Latency Service
2019/10/30 32

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GTP Decapsulation and Encapsulation
D = 1 −
𝑀𝑎𝑥 𝑃 − 36,46
𝑃
, 56 ≤ P ≤ 1500
46 Byte-1500 Byte
Header Payload CRC
4 Byte14 Byte

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Low Latency Service
2019/10/30 34
T = 𝑇𝑂𝑉𝑆,𝐸𝑃𝐶 + 𝑃𝐸𝑃𝐶 + 𝑇𝐸𝑃𝐶,𝐻𝑜𝑠𝑡
T′
= 𝑃𝑂𝑉𝑆 + 𝑇𝑂𝑉𝑆,𝐻𝑜𝑠𝑡

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Floating IP Architecture
2019/10/30 35
• In order to let remote host route the correct path, we
can’t directly use the IP of UE allocated by PGW.
• Controller provides operators assign an unused IP in
edge LAN to UEs.
• Controller handles the assigned IP flows.

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Initial GTP-U Protocol Stack
GTP OVS
eNBUE
A B
EPC
Gateway
Internet Host
D
C
E
DC
EC
Eth
IP
ED
EC
Eth
IP
EA
CB
CB
Eth
IP
GTP/IP
Src Dst
2019/10/30 36

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EPC
Floating IP Architecture(Uplink)
GTP OVS
eNBUE
A B
Gateway
Internet Host
D
E
DNil
EF
Eth
IP
EA
CB
CB
Eth
IP
GTP/IP
ED
EF
Eth
IP
F
C
Data Flow Direction
2019/10/30 37
pop_gtp
NilNil
EA
Eth
IP
pop_gtp_src

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TEID
BC
BC
Eth
IP
GTP
AEGTP/IP
EPC
Floating IP Architecture(Downlink)
GTP OVS
eNBUE
A B
Gateway
Internet Host
D
E
?D
FE
Eth
IP
DE
FE
Eth
IP
Controller
ARP Handler
Response eNB
Mac AddressF
Data Flow Direction
ARP Query
B
C
2019/10/30 38
push_gtp_dst &
push_gtp_teid
mod_nw_src &
mod_nw_dst
TEID
NilNil
NilNil
Eth
IP
GTP
AEGTP/IP

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Proposed Method
2019/10/31 39
• System Architecture
• GTP-Support OpenFlow Service
• Low-Latency Service
• Flow Redirecting Service

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Flow Redirecting Service
2019/10/30 40
eNB1
eNB2
UE
UE
UE
Openstack Cloud
EPC
Central OVS
SDN Controller
eNB3 EPC2

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Outline
2019/10/30 41
• Introduction
• Related Work
• Proposed Method
• Experiments
• Conclusion

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Experiments(1/21)
2019/10/30 42
• Development Environment
• Flow Diagram
• Simulation Environment
• Software Testing Tools
• Experimental Result
• Demo

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Experiments(2/21)
2019/10/30 43
• Development Environment
Hardware Software
ASUS X99-E
CPU : Intel® Core™ i7-5960X
Memory : 32 GB
Centos 7.7-1908
OpenStack-Queens
OpenAirInterface-openair-
cn
Acer M6630G
CPU : Intel® Core™ i7-4790
Memory : 8 GB
Ubuntu 16.04.3
OpenDaylight-Nitrogen SR3
Node.js-v10.16.0
Central Cloud
SDN Controller

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Experiments(3/21)
2019/10/30 44
• Development Environment
Hardware Software
ASUS MD790
CPU : Intel® Core™ i7-6700
Memory : 24 GB
Centos 7.6-1810
Open vSwitch-2.9.0
Acer M6630G
CPU : Intel® Core™ i7-4790
Memory : 8 GB
Ubuntu 16.04.3
OpenAirInterface-
openairinterface5g
Ettus USRP B210、B200 mini 2600 Mhz (Band 7)
Sony Xperia z3+、z5 Android 7.1.1
Edge OVS
eNB
UE
SDR board

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eNB1
GTP
OVS
OpenStack
Cloud
Controller
eNB2
UE1
UE2
USRP B210 USRP B200
mini

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Experiments(6/21)
2019/10/30 47
• Simulation Environment
Hop 1 times
Hop 4 times
noc.tanet.edu.tw
edith.cse.nsysu.edu.tw
140.117.168.x/24
140.117.169.x/24
140.117.193.x/24

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Experiments(7/21)
2019/10/30 48
• Software testing tools
◼IP Tools
◆IP Informatin
◆Pings
◼Test method
◆Send different size ICMP packets to
Edge/Internet Host
◆Circulate Fronthaul/Backhaul Latency
◆Test 1000 times

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Experiments(8/21)
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18 64 128 256 512 1024
Hop 4 EPC 1.237 1.347 1.416 1.546 1.816 2.397
Hop 1 EPC 0.776 0.915 0.989 1.014 1.179 1.479
FloatingIP 0.614 0.72 0.739 0.807 0.917 1.169
0
0.5
1
1.5
2
2.5
3
Latency(ms)
Packet Size(Byte)
Edge Host Backhaul Latency

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Experiments(9/21)
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18 64 128 256 512 1024
Hop 4 EPC 28.357 28.297 28.741 29.47 31.735 33.409
Hop 1 EPC 26.708 26.83 27.765 29.08 29.329 31.535
FloatingIP 24.028 24.518 27.5 27.702 28.928 30.748
0
5
10
15
20
25
30
35
40
Latency(ms)
Packet Size(Byte)
Edge Host Fronthaul Latency

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Experiments(10/21)
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18 64 128 256 512 1024
Hop 4 EPC 7.177 7.382 7.345 7.574 7.86 8.281
Hop 1 EPC 6.996 7.069 7.082 7.18 7.33 7.692
FloatingIP 6.78 6.856 6.916 7.016 7.085 7.38
0
1
2
3
4
5
6
7
8
9
Latency(ms)
Packet Size(Byte)
Internet Host Backhaul Latency

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Experiments(11/21)
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18 64 128 256 512 1024
Hop 4 EPC 36.181 35.149 37.635 37.649 38.158 38.367
Hop 1 EPC 32.476 34.304 37.599 37.416 38.919 38.926
FloatingIP 31.797 32.032 34.443 36.764 37.284 37.437
0
5
10
15
20
25
30
35
40
45
Latency(ms)
Packet Size(Byte)
Internet Host Fronthaul Latency

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Experiments(12/21)
2019/10/30 53
• Software testing tools
◼Speedtest
◆Downlink
◆Uplink
◼Test method
◆Send packets to Kaohsiung CNS server
◆Test 10 times

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Experiments(13/21)
2019/10/30 54
Test environment Uplink(Mbps) Downlink(Mbps)
Hop 4 EPC 7.998 16.6
Hop 1 EPC 8.159 16.67
Floating IP 8.262 2.135
• Throughput

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Experiments(14/21)
2019/10/30 55
• There is no PGW to buffer data.
– TCP Dup ACK,Out-of-Order,Retransmission.

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3GPP TS 22.261

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Experiments(16/21)
2019/10/30 57
• Software testing tools
◼Self-developed
◆Downlink
◆Uplink
◼Test method
◆Download different size packets from edge server in a
bit intervals
◆Test 30 times

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Experiments(17/21)
2019/10/30 58
64 128 256 512 1024
Hop 4 EPC 6.099 9.024 13.363 16.013 17.782
Hop 1 EPC 6.133 9.151 13.458 16.558 17.769
Floating IP 6.15 9.51 13.567 16.528 18.6
0
2
4
6
8
10
12
14
16
18
20
Throughput(Mbps)
Buffer Size(Byte)
UE Downlink Throughput

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Experiments(18/21)
2019/10/30 59
Self-test App Speedtest
Hop 4 EPC 7.467 7.998
Hop 1 EPC 7.505 8.159
Floating IP 7.536 8.262
7
7.2
7.4
7.6
7.8
8
8.2
8.4
Throughput(Mbps)
UE Uplink Throughput

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Experiments(19/21)
• Flow Redirecting Service
• Test EPC CPU loading 10 times in different
connections during Speedtest.
◆1 UE, 1eNB
◆2 UE, same eNB
◆2 UE, different eNB, same EPC

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Experiments(20/21)
0
5
10
15
20
25
30
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
EPCCPULoad(%)
Time(sec)
EPC Loading
1eNB,1UE 1eNB,2UE 2eNB,2UE

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Experiments(21/21)
2019/10/30 62
Uplink(Mbps) Downlink(Mbps) EPC Avg
Loading (%)
1eNB, 1UE 8.027 16.6 16.333
1eNB, 2UE 6.959 10.698 18.645
2eNB, 2UE 8.09 16.68 19.011
• Throughput and loading for same EPC

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Demo

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Demo

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Outline
2019/10/30 65
• Introduction
• Related Work
• Proposed Method
• Experiments
• Conclusion

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Conclusion
• We develop a GTP patch based on OVS, so that it can identify,
decapsulate and encapsulate UE’s GTP-U flow Traffic using
OpenFlow.
• Propose a mechanism to decrease backhaul latency based on
processing GTP-U packets in edge OVS.
• Based on NFV and SDN, our proposed architecture and GTP
patch pursues the 5G uRLLC specification.

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Thanks for your Listening!
2019/10/30 67