投影片 1 - 國立臺灣大學

投影片 1 - 國立臺灣大學

ALL-IP 4G NETWORK ARCHITECTURE FOR EFFICIENT MOBILITY AND RESOURCE MANAGEMENT YOUNG-JUNE CHOI, UNIVERSITY OF MICHIGAN KWANG BOK LEE AND SAEWOONG BAHK, SEOUL NATIONAL UNIVERSITY 2007 IEEE Wireless Communications R96725043 R96725011 R96725030 1 Outline Introduction on 3G cellular network 3G network architecture Introductions on ALL-IP 4G cellular network ALL-IP 4G cellular network architecture Pure ALL-IP 4G network Subnet-based 4G network

2 What is 3G access network? (wikipedia) 3G is the third generation of mobile phone standards and technology. 3G networks are wide area cellular telephone networks. It enable network operators to offer users a 1. Wider range 2. More advanced services 3. Achieving greater network capacity through improved spectral efficiency Ex: WCDMA, cdma2000 3 Complicated 3G network structure 4 4G introduction 4G networks are expected to integrate any kind of wireless netw ork with Ethernet based on all-IP, and become a packet-switching system.

All-IP Exploit IP to integrate circuit switching network and packet switching network into a uniform all-IP network. Every mobile device has a IP. Revolution Orthogonal frequency division multiplexing (OFDM) ( 802.11b 2Mb/s 802.11g 54Mb/s) Multiple input multiple output (MIMO) antennas OFDM MIMO 1 MIMO OFDM MIMO (IEEE 802.11n) Evolution Interworking with existing systems. 5 Converged 4G network 6 4Gs vision

Integrate any kind of wireless network with Ethernet based on all-IP, and become a packet-switching system. To support high mobility Exploit hybrid multiple access techniques. To support Data and voice traffic To increase throughput Integrated different Quality of Services 7 Mobile IP Source http://wnai.csie.ndhu.edu.tw/ITS/news/courseware.ht m Home address Register Co A for IP upd ating Obtain CoA (Care-of Address) 8

Handoff Handoff Whenever a mobile terminal moves into another cell, it requires handoff to another base station. Handoff Latency 3 phases of a handoff: Scanning (most time-consuming) Authentication Re-association 9 ALL-IP cellular network architecture The pure all-IP 4G network (2003) The subnet-based 4G network 10 Outline Network architecture all-IP cellular network Network architecture for efficient

multiple access 11 Network Architecture All-IP Cellular Network Existing cellular network base station (BS) fast power control wireless scheduling base station controller (BSC) mobile terminal (MT) 12 4G Network Functions of BS BS acts the role of an access router (AR) 13 4G Network

Mobile IP (MIP) addresses for handoff incur high overhead hinders from performing smooth handoff Use high frequency band and result in short cell residence time latency is a challenging issue fast handoff scheme for address resolution delay 14 Subnet-based Network Separate the functionality of an AR AR takes L3 protocol access point (AP) takes L2 protocol 15 Subnet-based Network A subnet consisting of an A

R and several APs An MT moving within the s ubnet performs L2 handoff An MT moving into another AR area performs L3 hando ff 16 Comparison Pure all-IP network Subnet-based all-IP network Access network components AR AP + AR Operation type

Decentralized Centralized Handoff overhead High Low Handoff protocol L3 L2 + L3 Cost Low

High Advantage Architecture is simple and cost-efficient for implementation Efficient to resource management Disadvantage Long handoff latency High signaling Architecture is inflexible 17 Comparison Pure all-IP network

Subnet-based all-IP network Access network components AR AP + AR Operation type Decentralized Centralized Handoff overhead High Low

Handoff protocol L3 L2 + L3 Cost Low High Advantage Architecture is simple and cost-efficient for implementation Efficient to resource management Disadvantage

Long handoff latency High signaling Architecture is inflexible 18 Comparison Pure all-IP network Subnet-based all-IP network Access network components AR AP + AR Operation type

Decentralized Centralized Handoff overhead High Low Handoff protocol L3 L2 + L3 Cost Low High

Advantage Architecture is simple and cost-efficient for implementation Efficient to resource management Disadvantage Long handoff latency High signaling Architecture is inflexible 19 Network Architecture for Efficient Multiple Access Cells are categorized into: Macrocells deployed in rural

Microcells deployed in urban Picocells deployed in building User are categorized into: High-mobility users (macrocells) Low-mobility users (microcells) 20 Macrocells and Microcells MT can access macrocells and micro cells macrocells cover high speed MT microcells cover low speed MT 21 OFDMA v.s. FH-OFDMA OFDMA FH-OFDMA Combinatio n

OFDM and FDMA Frequency-hopping and OFDMA Advantages Higher allocation granularity High spectral efficiency Support various data rate by AMC Exploit diversity High mobility Overcome channel fading and multi-user interference Disadvanta ge Limited to low mobility

Difficult in supporting high data rates and AMC (adaptive modulation and coding) Mobility Microcells for low mobility Macrocells for high mobility If an MTHigh can support dual modes, it can sw rate data services Low rate data services itch cells in a manner of using vertical han doff Traffic type 22

OFDMA v.s. FH-OFDMA OFDMA FH-OFDMA Combinatio n OFDM and FDMA Frequency-hopping and OFDMA Advantages Higher allocation granularity High spectral efficiency Support various data rate by AMC Exploit diversity High mobility Overcome channel fading and

multi-user interference Disadvanta ge Limited to low mobility Difficult in supporting high data rates and AMC (adaptive modulation and coding) Mobility Microcells for low mobility Macrocells for high mobility If an MTHigh can support dual modes, it can sw rate data services Low rate data services

itch cells in a manner of using vertical han doff Traffic type 23 OFDMA v.s. FH-OFDMA OFDMA FH-OFDMA Combinatio n OFDM and FDMA Frequency-hopping and OFDMA Advantages Higher allocation granularity

High spectral efficiency Support various data rate by AMC Exploit diversity High mobility Overcome channel fading and multi-user interference Disadvanta ge Limited to low mobility Difficult in supporting high data rates and AMC (adaptive modulation and coding) Mobility Microcells for low mobility Macrocells for high mobility

If an MTHigh can support dual modes, it can sw rate data services Low rate data services itch cells in a manner of using vertical han doff Traffic type 24 OFDMA v.s. FH-OFDMA OFDMA FH-OFDMA Combinatio n OFDM and FDMA

Frequency-hopping and OFDMA Advantages Higher allocation granularity High spectral efficiency Support various data rate by AMC Exploit diversity High mobility Overcome channel fading and multi-user interference Disadvanta ge Limited to low mobility Difficult in supporting high data rates and AMC (adaptive

modulation and coding) Mobility Microcells for low mobility Macrocells for high mobility If an MTHigh can support dual modes, it can sw rate data services Low rate data services itch cells in a manner of using vertical han doff Traffic type 25 OFDMA v.s. FH-OFDMA OFDMA

FH-OFDMA Combinatio n OFDM and FDMA Frequency-hopping and OFDMA Advantages Higher allocation granularity High spectral efficiency Support various data rate by AMC Exploit diversity High mobility Overcome channel fading and multi-user interference

Disadvanta ge Limited to low mobility Difficult in supporting high data rates and AMC (adaptive modulation and coding) Mobility Microcells for low mobility Macrocells for high mobility If an MTHigh can support dual modes, it can sw rate data services Low rate data services itch cells in a manner of using vertical han doff

Traffic type 26 OFDMA v.s. FH-OFDMA OFDMA FH-OFDMA Combinatio n OFDM and FDMA Frequency-hopping and OFDMA Advantages Higher allocation granularity High spectral efficiency Support various data

rate by AMC Exploit diversity High mobility Overcome channel fading and multi-user interference Disadvanta ge Limited to low mobility Difficult in supporting high data rates and AMC (adaptive modulation and coding) Mobility Microcells for low mobility Macrocells for high mobility If an MTHigh

can support dual modes, it can sw rate data services Low rate data services itch cells in a manner of using vertical han doff Traffic type 27 OFDMA v.s. FH-OFDMA OFDMA FH-OFDMA Combinatio n OFDM and FDMA Frequency-hopping and OFDMA

Advantages Higher allocation granularity High spectral efficiency Support various data rate by AMC Exploit diversity High mobility Overcome channel fading and multi-user interference Disadvanta ge Limited to low mobility Difficult in supporting high data rates and AMC (adaptive modulation and coding)

Mobility Microcells for low mobility Macrocells for high mobility If an MT can support dual modes, it can sw High rate data services Low rate data services e.g., voice itch cells in a manner of service using vertical han doff Traffic type 28 OFDMA v.s. FH-OFDMA OFDMA FH-OFDMA Combinatio

n OFDM and FDMA Frequency-hopping and OFDMA Advantages Higher allocation granularity High spectral efficiency Support various data rate by AMC Exploit diversity High mobility Overcome channel fading and multi-user interference Disadvanta ge Limited to low mobility

Difficult in supporting high data rates and AMC (adaptive modulation and coding) Mobility Microcells for low mobility Macrocells for high mobility If an MT can support dual modes, it can sw High rate data services Low rate data services e.g., voice itch cells in a manner of service using vertical han doff Traffic type 29 QoS of wireless access network

In general, a wireless access networ k becomes a bottleneck for providin g end-to-end QoS. To support IP QoS, the Internet Engi neering Task Force (IETF) recomme nds integrated services (IntServ) differentiated services (DiffServ) 30 IntServ IntServ uses Resource Reservation Protocol (RSVP) to reserve bandwidt h during the session setup. IntServ ensures strict QoS, but each router must implement RSVP and m aintain per-flow state, which can ca use difficulties in a large scale netw ork. 31 DiffServ In DiffServ, the QoS level of a packet i

s indicated by the DS field of IP heade r, so that differential levels of service can be given to different aggregate flo ws at the entry points to the network. Since DiffServ is not so rigorous as Int Serv, it is scalable in supporting QoS s tatistically. 32 QoS of wireless access network (cont d) The importance of unified QoS man agement grows in 4G networks as QoS management for both access networks and IP networks becomes cumbersome in all-IP networks. 33 QoS of wireless access network (cont d) 3GPP (third generation partnership p

rojects) define four traffic classes an d their related parameters for QoS pr ovisioning. However, direct translation is difficul t since access networks have their o wn QoS attributes that require strict QoS provisioning within them. 34 ITRAS IP-Triggered Resource Allocation Str ategy ITRAS concerns the information abo ut IntServ and DiffServ for the resour ce management of L1 and L2. Cell type: microcell or macrocell Multiple access: OFDMA or FH-OFDMA MAC channel: dedicated or shared PHY scheduling: priority or fairness 35 ITRAS (contd) For example, when an MT requests

a real-time service, the correspond ing AR can initiate IntServ and MAC reserves a dedicated channel. In contrast, when DiffServ is used f or low mobility users, MAC can exp olit either a dedicated or a shared channel. 36 ITRAS (contd) 37 ITRAS (contd) 38 ITRAS (contd) There are other issues to be consid ered How an AR cooperate with its subordi nate AP in performing ITRAS functions .

Load balancing in macrocell and micr ocell. 39 Conclusion This article discusses a new approa ch for designing an architecture an d QoS model which cover L1 throu gh L3 in 4G network . Subnet-based cell structure Combine the multiple access schemes with cell selection Unified QoS strategy 40

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