Title: UTDETRI Mid year project presentation
1UTD-ETRI Mid year project presentation
- Shanthy Menezes, S. Venkatesan
- UT-Dallas
2Characteristics of Interworking Scenarios2
3Research on Interworking Architectures
- Broadband Radio Access Networks (BRAN) by ETSI3
- WLAN-GPRS integration by Salkintzis et al.4
- Evaluation of architectures by Tsao and Lin5
4BRAN by ETSI
- Two architectures defined for interworking
between HIPERLAN/2 and 3G systems - Loose coupling is defined as the utilization of
HIPERLAN/2 as an access network complementary to
current 3G access networks, utilizing the
subscriber databases but without any user plane
Iu type interface, i.e. avoiding the SGSN, GGSN - Connecting HIPERLAN/2 network to the rest of the
UMTS network (the core network) in the same
manner as other UMTS radio access technologies
(UTRAN, GERAN) using a new interface is termed
Tight Coupling.
5Tight Coupling Architecture of BRAN
6Tight Coupling for WLAN-GPRS Integration
7Tight Coupling Protocol Architecture
8Loose Coupling for WLAN-GPRS Integration
9WLAN Authentication Protocols for Loose Coupling
10Tight Coupling using RNC Emulator
11Performance Evaluation by Tsao and Lin
12Architecture Comparisons
13Architecture Comparisons
14Architecture Comparisons
15Handover Categories
- Horizontal Handover (HO)
- HO between base stations utilizing the same radio
access technologies - Vertical Handover
- HO between base stations that use different radio
access technologies
16Vertical HO Categories
17Handover Algorithms
Traditional
High Complexity
Vertical HO based on prediction
18Traditional Algorithms
Input Value V Received Signal Strength OR Signal
to Interference Ratio
If V from old BS lt Threshold Value then HO to
new BS
If V from new BS gt V from old BS then HO to new
BS
If V from new BS gt V from old BS Hysterisis h
then HO to new BS
If (V from old BS lt Threshold Value) AND (V from
new BS gt V from old BS Hysterisis h) then HO
to new BS
19Traditional AlgorithmsDirection Biased
Handover To BS2
Candidate BS 1
Mobile Direction
Candidate BS 2
Signal Strength from BS1
Signal Strength from BS2
20Traditional Algorithms
- Distance Based
- HO to the nearest BS
- Velocity Adaptive
- Employ a variable hysterisis and threshold based
on mobiles velocity
21High Complexity Algorithms
- Dynamic Programming Based
- Utilizing Patter Recognition
- Neural Network Based
- Fuzzy Logic Based
22Vertical HO Algorithms
- Hybrid Information System (HIS) based HO by Lott
et al. 6 - HO in mobile data networks by Pahlavan et al 7
- Location Assisted HO by Leeuwen et al.8
23HIS based HO
24Pahlavan et al
25Location Assisted HO
- Best suited for fast vehicular users.
- Assumptions
- Measurement reports of the mobile are available
in the current network (WLAN or UMTS). - and
- Mobile periodically sends its GPS coordinates to
the current network.
26Location Assisted HO Algorithm
- Predict what the mobile location will be when it
sends the next measurement report. - Calculate the probability P, that at this
location HO is required. - If P gt Threshold initiate HO
27Our Contribution
28Fast MIPv6 Handover (Predictive)
29Fast MIPv6 Handover (Predictive)
MN detects new AP (link specific method)
Router Sol for Proxy Adv
Proxy Router Adv
Fast Binding Update
HI
Hack
Fast Binding Ack
Fast Binding Ack
Disconnect
Forward packets
Disconnect
Fast Neighbor Advertisement
Deliver packets
MN
Previous AR
New AR
30Fast MIPv6 Handover (Reactive)
MN detects new AP (link specific method)
Router Sol for Proxy Adv
Proxy Router Adv
Disconnect
Connect
FNA FBU
Fast Binding Update
Fast Binding ack
Forward packets
Deliver packets
MN
Previous AR
New AR
313GPP-WLAN Interworking System1
32FMIPv6 based Fast HO in UMTS-WLAN
- GGSN Router that provides IP access to MN in
UMTS - PDG Router that provides IP access to MN in WLAN
- GGSN and PDG participate in fast HO
33WLAN to UMTS HO
- Network provides three link layer triggers to MN
- Trigger one MN detects movement to new subnet
- Trigger two MN starts pre-authentication
- Trigger 3 MN initiates FBU and then HO
34Movement Detection
Router Sol for Proxy Adv
Construct response containing Prefix, IP address
and L2 address
Proxy Router Adv
PDG
MN
35Pre-authentication
- Without using UMTS interface
- Activate UMTS interface and use UMTS
36Pre-authentication without UMTS interface
- MN sends GPRS attach to SGSN through WLAN
interface (via WAG) - SGSN authenticates by communicating with
HLR/HSS/AuC - After authentication, state of MN at SGSN and MN
PMM_IDLE - GPRS attach procedure is executed while UMTS
interface is in receive mode - Need interface between WAG and SGSN
- Protocol stack at MN and WAG needs to be modified
37Pre-authentication using UMTS Interface
- Initially, UMTS interface of MN in receive mode
- MN transmits on UMTS interface
- Perform GPRS attach
- After successful GPRS attach, UMTS interface
returns to receive mode
38After pre-authentication
FBU
HI
HACK
Setup tunnel between Previous CoA and New CoA
Disconnect from WLAN and connect to UMTS
Fast Neighbor Advertisement
Deliver tunneled packets
BU to HA and CN
MN
PDG
GGSN
39UMTS to WLAN HO
- In addition to network provided triggers, MN has
internal triggers
40Movement Detection
Router Sol for Proxy Adv
Construct response containing Prefix, IP address
and L2 address
Proxy Router Adv
GGSN
MN
41Pre-authentication
- Without using WLAN (using only UMTS interface)
- Activate WLAN interface and use WLAN
42Pre-authentication without WLAN interface
- MN performs EAP authentication and authorization
procedure via UMTS - Change state of MN to WLAN-attach
- Needs
- EAP over WLAN is to run on UTRAN (modification
needed) - Wg interface between WAG and 3GPP AAA server
needs enhancement for exchanging EAP messages
43Pre-authentication using WLAN Interface
- Initially, WLAN interface of MN in receive mode
- MN transmits on WLAN interface
- Perform EAP authentication
- Change WLAN to receive mode
44After pre-authentication
FBU
HI
HACK
Setup tunnel between Previous CoA and New CoA
Disconnect from UMTS and connect to WLAN
Fast Neighbor Advertisement
Deliver tunneled packets
BU to HA and CN
MN
GGSN
PDG
45HO Trigger to Aid FMIP6
- Challenges
- When to trigger?
- Predicting the next Access Point?
46When to Trigger?
47Inputs to Prediction Algorithm
- Signaling strength of neighboring APs.
- Direction of the mobile.
- Geographical terrain information Consists of
terrain map with position of APs and possible
directions for users while on this terrain. - Handover history with direction A list of (AP1,
?, AP2, Rating), where the Rating increases each
time the mobile goes from AP1 to AP2 while moving
in the direction ?.
48Inputs to Prediction Algorithm
- Path history A history of sequence of APs
traversed by all mobiles. - Current Path The current sequence of APs
traversed by the mobile. - Map of coverage areas of all neighboring APs.
49Prediction AlgorithmStep I
50Prediction AlgorithmStep II
51Prediction AlgorithmStep III
52Prediction AlgorithmStep IV
53Prediction AlgorithmStep V
54Prediction AlgorithmStep VI Choose Best AP
55OPNET Modeler
- Modeling using Finite State Machine
- Programming Language C/C
- Most networks already modeled
56OPNET Modeling Domains
57802.11 WLAN in OPNET
58UMTS network in OPNET
59Availabe features of Mobile IPv6 in OPNET
- Supported Mobility Features
- Route optimization
- Mobile node (MN)home agent (HA) bi-directional
tunneling - Available IPv6 extension headers
- Mobility extension headers
- Routing (type 2) and destination option extension
headers
60WLAN-3G intworking in OPNET
- New nodes to build
- Dual mode User Equipment (UE)
- AAA Server
- Wireless Access Gateway (WAG)
- Packet Data Gateway (PDG)
61WLAN-3G intworking in OPNET
- New interfaces to add
- Ww - Interface between the UE and the WLAN Access
Network - Wn - Interface between the WLAN Access Network
and the WAG. - Wp - Interface between the WAG and PDG.
- Wm Interface between point is located between
3GPP AAA Server and PDDG
62Other additions to OPNET
- Fast Mobile IPv6 extensions to the existing
Mobile IPv6. - Node to execute the HO Algorithms.
63Future Plans (current project year)
- Opnet simulation for validation
- Choose parameters for prediction based on
extensive simulation - Measure prediction accuracy
64Future Plans (after current project)
- Can we generalize to HO between any RAT and any
RAT?
65REFERENCES
- 3gPP TS23.234 v 6.4.0, 3GPP system to Wireless
Local Area Network interworking system
description 3GPP specifications. - 3gPP TS22.934 v 6.4.0, Feasibility study on 3GPP
system to Wireless Local Area Network
interworking. 3GPP specifications. - ETSI TR 101 957
- A.K. Salkintzis, C. Fors, and R. Pazhyannur.
WLAN-GPRS Integration for Next-Generation Mobile
Data Networks, IEEE Wireless Communication, pp.
112-124, October, 2002. - S. Taso and C. Lin, Design and Evaluation of
UMTS-WLAN Interworking. Strategies, IEEE VTC
2002 Fall, vol. 2, pp. 777-781, Sep. 2002 - Lott et al. Interworking of WLAN and 3G
systems. Communications, IEE Proceedings- Volume
151, Issue 5, 24 Oct. 2004 Page(s)507 513 - K. Pahlavan et al., Handoff in Hybrid Mobile
Data Networks IEEE Pers. Commun., Apr. 2000. - Leeuwen et al. Location assisted fast vertical
handover for UMTS/WLAN overlay networks
International conference on wired/wireless
internet communications (WWIC) 2005.