Cloud Evolved Packet Core Network Architecture Based on
SDN
Zhang Yaoyun
1, a
, Xu Zhan
1, b
and Tian Zhigang
2, c
1
Beijing Information Science & Technology University, Beijing, 100192, China.
2
Tsinghua University, Beijing, 100084, China.
a
zhangyaoyun111@126.com,
b
xuzhan@bistu.edu.cn,
c
zgtian@tsinghua.edu.cn
Keywords
:SDN , Openflow , CEPC , Signaling load
Abstract.This paper proposes a Cloud Evolved Packet Core (CEPC) architecture
based on software-defined networking (SDN) / Openflow technology, which separates
the control plane and data plane of a serving gateway (SGW) and a PDN gateway
(PGW) completely, and runs the control functions of a mobility management entity
(MME), SGW-C and PGW-C of the LTE-evolved packet core (LTE/EPC)
architecture in the cloud controller. By simulating the initial attach process of the
CEPC architecture and the traditional LTE / EPC architecture, it is concluded that the
CEPC architecture has a lower paging signaling load, and the network flexibility and
programmability are higher.
1.Introduction
With the expansion of modern mobile network services and the expansion of the
scale of Internet applications, the operation and management of network complexity
increases, the cost becomes high. It presents a huge challenge to the current mobile
network architecture. The 3GPP LTE/EPC and LTE-A
[1]
standards were released to
cope with the increased demand for high-speed mobile networks. However, LTE /
EPC architecture still faces some problems, such as the data plane at the SGW and the
PGW is still tightly coupled with the control plane.
In this paper, based on the LTE/EPC architecture, the use of SDN/Openflow
technology
[2]
to redesign the architecture, that is, the CEPC system architecture. The
architecture is flexible and programmable by completely separating the control plane
and the data plane. By comparing the initial attach process of traditional LTE / EPC
architecture and CEPC architecture ,the signaling load of the process
[3]
as an
evaluation metric, the CEPC architecture is superior to the traditional architecture in
the case of different number of users.
2.Background and Related Work
2.1 3GPP LTE / EPC architecture:
3GPP LTE / EPC
[4]
architecture is mainly responsible for the overall control of
the user terminal and the establishment of the relevant bearer. The EPC architecture is
mainly composed of MME, SGW, PGW and the Home Subscriber Server (HSS),as
shown in Fig.1. The user sends data packets through the eNB and SGW to the PGW.
The MME is a control node that handles signaling interactions between the UE and
the core network. SGW and PGW are responsible for data forwarding, IP address
assignment, and Quality of Service(QoS) assurance in the data plane.