Download all-ip 4g network architecture for efficient mobility and resource

ALL-IP 4G NETWORK
ARCHITECTURE FOR EFFICIENT
MOBILITY AND RESOURCE
MANAGEMENT
Authors:
YOUNG-JUNE CHOI, UNIVERSITY OF MICHIGAN
KWANG BOK LEE AND SAEWOONG BAHK, SEOUL
NATIONAL UNIVERSITY
Source: IEEE Wireless Communications, 2007
老師: 連耀南 教授
學生: 邱淑怡 (97753506)
Outline
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Introduction
Network architecture ALL-IP cellular network
Network architecture for efficient multiple
access
IP-triggered resource allocation
strategy(ITRAS)
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IP QoS
QoS of wireless access networks
ITRAS
Conclusion
2
Introduction – 4G
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4G networks
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4G networks have two different visions:
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an all-IP based packet-switched system
similar to the IP backbone network
revolution— developing an innovative system
evolution — interworking with existing systems
This model covers a future scenario of
ubiquitous networking
Develop an innovative system with high
throughput and wide coverage
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Introduction - technique
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The new techniques
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orthogonal frequency division multiplexing (OFDM)
multiple input multiple output (MIMO) antennas
IEEE 802.16 standard sets a goal of WMAN
/WLAN based on OFDM or orthogonal
frequency division multiple access (OFDMA)
developed a hybrid multiple access scheme
combining OFDMA and frequency hopping
(FH)-OFDMA, where fast-moving users access
the network via FH-OFDMA
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簡述OFDMA/FH-OFDMA
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OFDMA：個別或是一組tone可以分配給不同使
用者，多個用戶可以利用這種方式來分享頻寬，
可以和跳頻技術結合，以得到和CDMA相同的
好處
FH-OFDMA：在OFDMA系統的基礎上加入跳
頻的技術，以提高系統效能。依據預先確定的
跳頻序列，系統給各個使用者分配需要的頻率
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It can overcome channel fading and multi-user
interference through an FH pattern
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FDM  OFDM
Orthogonal Code:每個碼相加之後並不會干擾到另一
個正交碼
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Frequency Division Multiplexing
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OFDM frequency dividing
EARN IN SPECTRAL EFFICIENCY
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TDMA/OFDM/OFDMA
Source : Orthotron Corp.
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Introduction
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a new wireless network comprised
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OFDMA microcells
FHOFDMA macrocells
Innovative 4G systems
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medium access control (MAC) layer  L1
physical (PHY) layer  L2
Cover the network layer  L3
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Goal
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Explain two models of all-IP cellular
network architecture
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develop a subnet-based network that can
support L2 and L3 handoffs separately and
compare it with a pure all-IP network
Design a hierarchical cellular network that
consists of microcells and macrocells
Present a quality of service (QoS) support
methodology that tightly couples all three
layers
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Network architecture ALL-IP
cellular network
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4G network has a simple structure where
each BS must function intelligently to
perform radio resource management as well
as physical transmission
BSaccess router (AR)
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Network architecture ALL-IP
cellular network
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MT configures mobile IP (MIP) addresses for
handoff
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takes several seconds to run the MIP handoff and
MIP hinders an MT from performing smooth
handoff
reducing the latency is still a challenging issue
Fast handoff scheme proposes to decrease the
address resolution delay by pre-configuration
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Network architecture subnet based
cellular network
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separate the functionality of an AR from that
of an access point (AP) so that each
undertakes L3 and L2 protocols
AR manages several AP
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BSC vs BS
A subnet includes
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an AR and several AP
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Compared two network architecture
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Pure all-IP  decentralized
Subnet-based all-IP  centralized
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pure all-IP network incurs L3 protocol in the
end access link, it requires long handoff latency
and high signaling overhead
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Network architecture for efficient
multiple access
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Cells
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Macrocells are deployed in rural regions
Microcells are deployed in urban regions
Picocells are deployed in buildings
Designed a service model by mobility, such that
macrocells and microcells cover high speed and
low speed MT
hierarchical cell structure by integrating
multiple access techniques
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Based on OFDMA
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Network architecture for efficient
multiple access
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Cells handle traffic classes differently
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High rate data services are suitable for OFDMA
Low rate data services(voice) are adequate for
FH-OFDMA
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It’s difficult in supporting high data rates and AMC
(adaptive modulation and coding)
OFDMA microcells & FH-OFDMA macrocells
can support various users with different
mobility and traffic types
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Network architecture for efficient
multiple access
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IP-triggered resource allocation
strategy(ITRAS)
IP QoS
 QoS of wireless access networks
 ITRAS
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IP QoS
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IETF recommends integrated services (IntServ)
and differentiated services (DiffServ) for IP QoS
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IntServ: each router must implement
RSVP(Resource Reservation Protocol), IntServ
ensures strict QoS, cause difficulties in a large-scale
network
DiffServ: the packet is classified, each router can
mark, shape, or drop it according to network traffic
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QoS of wireless access networks
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The importance of unified QoS management
grows in 4G networks as QoS management
for both access networks and IP networks
becomes cumbersome in all-IP networks
In ITRAS, L1 and L2 allocate radio resources
and logical channels, respectively, according
to the QoS indication of L3
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ITRAS
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ITRAS concerns the information about IntServ
and DiffServ for the resource management of
L1 and L2
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When IntServ establishes a real-time session, MAC
reserves a dedicated channel
when DiffServ is used for low mobility users, MAC
can exploit either a dedicated or a shared channel
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ITRAS
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IP QoS information helps MAC and PHY
manage the following resources in a flexible
manner
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Cell type – microcell or macrocell
Multiple access – OFDMA or FH-OFDMA
MAC channel – dedicated or shared
PHY scheduling – priority or fairness
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ITRAS
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MT requests a real-time service in 4G, the
AR can initiate IntServ and allocate a
dedicated channel
For a downlink call, AR can adjust the
bandwidth of a dedicated channel with the
aid of RSVP
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ITRAS
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Conclusion
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Discuss a new approach for designing an
architecture and QoS model in 4G
A subnet-based cell structure that consists of
AP and AR, each handling L2 and L3 handoffs.
Combine the multiple access schemes of
OFDMA and FH-OFDMA
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mobile speed and traffic types
Design a unified QoS strategy, named ITRAS
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IntServ and DiffServ can determine resource
attributes
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Thanks for your attention