Transcript Use Cases

Vertical Handovers in Heterogeneous
Next-Generation Wireless Networks
Prof. George Kormentzas,
University of the Aegean
Presentation Outline



Mobility in the heterogeneous next-generation networking
environment
 The handover process
Mobility management protocols from IETF
The IEEE 802.21 approach
 Analogies to SNMP
 Mediation Bus
2
The Heterogeneous Next-Generation Wireless
Environment

Diverse access networks, with coverage at different ranges and
capacity at different levels, interconnected through a common
IP-based core
Applications
Broadcast
2G
3G
IP-based Core
WiMAX
WiFi
LTE
3
Today's Perspective
Virtual Mobile Operator
Virtual Mobile
Operator Subscriber
BSS+OSS Functions
Billing, Provisioning,
etc...
Mobile Operator
Mobile Operator
Subscriber
BSS+OSS Functions
Billing, Provisioning, AAA,
etc...
Today's Perspective
Use Cases:
- New Subscription
- Making a Call
- Billing
Virtual Mobile
Operator Subscriber
Virtual Mobile Operator
BSS+OSS Functions
Billing, Provisioning, etc...
Mobile Operator
BSS+OSS Functions
Billing, Provisioning, AAA,
etc...
Today's Perspective
Use Cases:
- New Subscription
- Making a Call
- Billing
Virtual Operator
Subscriber
Virtual Mobile Operator
BSS+OSS Functions
Billing, Provisioning, etc...
Mobile Operator
BSS+OSS Functions
Billing, Provisioning, AAA,
etc...
Today's Perspective
Use Cases:
- New Subscription
- Making a Call
- Billing
Virtual Operator
Subscriber
Virtual Mobile Operator
BSS+OSS Functions
Billing, Provisioning, etc...
Mobile Operator
BSS+OSS Functions
Billing, Provisioning, AAA,
etc...
Tomorrow's Perspective
Virtual Mobile Operator
BSS+OSS Functions
Billing, Provisioning, AAA,
etc...
Virtual Operator
Subscriber
Local Operator
Subscriber
WiMax
Operator
1
WiMax
Operator
2
Cable Operator
1
Cable Operator
2
Mobile
Operator
1
Mobile
Operator
2
HotSpot Owner
1
HotSpot Owner
2
HotSpot Owner
...
Technical Issues
•
Mobile IP Roaming (transparent to the
subscriber)
•
Inter-Domain Handover (HO)
•
Mobile Node (MN) Network Preferences Steering
•
Inter-Domain Billing (on a large scale number
of peer domains)
Business Issues
•
•
•
•
Introduction (acceptance) of new components such as
Global Auction Market
Addition of new features in already existing components
such as Clearing Houses
Use of operators signalling infrastructure
Real-Time billing
Mobility Management in Heterogeneous Networks

Mobility is a key issue in future heterogeneous
environments

Mobility management is comprised of 2 components:



Location management (facility to find where a Mobile Node is located so
as to initiate service)
Handover management (facility to allow a Mobile Node to keep its
connection active when changing point of attachment to the
network)
Today, mobility is supported in several cellular and
wireless technologies.
11
Handover Types

With respect to the technology



With respect to administrative domain



Intra-domain
Inter-domain
With respect to whether resources are allocated in advance in
target network



Intra-technology (Horizontal)
Inter-technology (Vertical)
Backward (resources are reserved)
Forward (resources are not reserved)
With respect to the entity that initiates the handover


Network-initiated
Mobile-initiated
12
Vertical Handover Use cases

Coping with imminent network unavailability



Opting for extra or better service


Mainly due to movement causing degradation of the signal
strength
Also due to maintenance work scheduled by the network
operator
Better in this case can be: cheaper, more secure, enhanced,
etc.
Optimizing radio resource usage

Mainly driven by the operator for better utilization of the
resources
13
Benefits

For operators




Increased system capacity and better load management
Provision of better services to subscribers in areas where the
coverage of one of the networks is not good or demand for
services high
Revenues from roaming agreements with other operators
For users

Always best connected

Best connection according to QoS, cost, user preferences, power
consumption, etc.
14
Use Cases -> Actual Implementations
Scenarios



Imminent network unavailability
Improvement of offered services
Optimization of network resource usage
Implementations of Use Cases






Leaving the office (handover from Wi-Fi to WiMAX)
Emergency medical support (handover from Wi-Fi to UMTS to
WiMAX)
Arriving at the airport (handover from UMTS to Wi-Fi)
Mobile TV on a train (handover from DVB to Wi-Fi)
Improving service experience (handover from WiMAX to UMTS)
Releasing resources for other services (handover from WiMAX to
DVB).
15
Reference Scenarios

Scenario 1: Coping with imminent network unavailability



Scenario 2: Opting for extra and better services



Use Case 1: Leaving the Office (Wi-Fi to WiMAX)
Use Case 2: Emergency Medical Support (Wi-Fi to UMTS to WiMAX)
Use Case 3: Arriving at the airport (UMTS to Wi-Fi)
Use Case 4: Mobile TV on a Train (DVB to Wi-Fi)
Scenario 3: Optimizing Radio Resources Usage

Use Case 5: Improving service Experience (WiMAX to UMTS)

Use Case 6: Releasing resources for other Services (WiMAX to DVB)
16
Reference Scenarios

Scenario 1: Coping with imminent network unavailability

Use Case 1: Leaving the Office (Wi-Fi to WiMAX)
Reference Scenario 1 flow chart
17
Reference Scenarios

Scenario 2: Opting for Extra and Better Services

Use Case 4: Mobile TV on a Train (DVB to Wi-Fi)
Reference Scenario 2 flow chart
18
Reference Scenarios

Scenario 3: Optimizing Radio Resources Usage

Use Case 5: Improving Service Experience (WiMAX to UMTS)
Reference Scenario 3 flow chart
19
Services

Voice over IP

Video Tele Conferencing

Audio Streaming

Video Streaming

Interactive Games

HTTP Services

Email Download
20
The Handover Process (1/2)

Handovers occur when a mobile node changes its
Layer-2 network Point of Attachment (PoA)


i.e., the end-point of a L2 link between the mobile node and
the network (e.g., WLAN Access Point)
This L2 handover may subsequently trigger
reconfiguration of the mobile node’s IP address used as
location identifier (L3 handover)
21
The Handover Process (2/2)

3 phases: Initiation, Preparation & Execution
Handover Initiation
User & Operator
Policies
Applications QoS
requirements
Available networks
& resources
Handover Triggers
Target network selection
Handover Preparation
(resources reservation, connection establishment)
Handover Execution
(data forwarding, location updates)
22
Phases of the Handover Process (1/3)
 Handover
Initiation
 Compilation of information about
 Application QoS requirements
 User preferences
 Operator policies (shaped according to regulatory
constraints)
 Available networks
 Establishment of firm
 Need for the handover
 Target network
decisions on
23
Phases of the Handover Process (2/3)
 Handover
Preparation
 Actions
that can be taken in advance to
mitigate the impact of handover execution
 Resource
allocation to the target network
 L2 authentication and association
 Movement detection
 IP parameters configuration for the target network
 Preparations for data forwarding from previous to target
network
24
Phases of the Handover Process (3/3)
 Handover
Execution
 Connection
to target network
 Location
update
 Forwarding of data until location update is completed
 Release of resources in previous network
25
HO Evaluation
Performance metrics




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HO delay
Packet loss
Out of sequence packets
Signaling overhead
Power consumption
Call drop probability
Probability of false HO
26
Who makes Standards for Handovers

Handovers within the same technology are addressed
by the corresponding Standard Development
Organizations

3GPP, 3GPP2, IEEE, DVB
Handovers between heterogeneous technologies are
addressed mainly by the IETF
 The interoperability required to realize the B3G vision
calls for coordinated actions and integrated solutions to
mitigate the effects of handovers (delays and packet
losses)


Today we see joint efforts from 3GPP, IETF, DVB, IEEE
27
Network-layer Mobility Management Protocols
from IETF
 Terminal-based
Terminals are involved in handover signaling
 Need for special software in terminals
 Examples: Mobile IP (MIP), Hierarchical MIP, Fast
MIP

 Network-based
A relatively new concept in IETF
 Mobility support is provided by the network
 Example: Proxy MIP

28
Overview of Mobile IPv4
HomeAddr.
CN
Address Mapping Table
HomeAddr1
HomeAddr2
…
CoA1
CoA2
…
HA
HN
Data from CN to MN
Data from CN to MN
Data from MN to CN
Data from MN to CN
ANG
Signaling
Anchor Point
for both local
& global
mobility
FA
FA
CoA
FA
PoA
PoA
PoA
AN
PoA
29
MIP - Remarks



MIP provides the basis for terminal mobility management
It does not differentiate between global and local mobility
Enhancements to basic MIPv4 functionality allow for direct
communication between Correspondent Node (CN) and Mobile
Node (route optimization)


In MIPv6



In this case, however, the CN must be mobility-aware
Foreign Agents (FAs) are not needed (there is no problem with limited
addresses)
Route optimization is supported as a standard feature
MIP introduces significant delay due to procedures like



Movement detection
New Care-of Address (CoA) configuration
Location update
30
Overview of Hierarchical MIPv6
CN
GMAP
HN
ANG
Data from CN to MN
Data from MN to CN
Signaling
Anchor Point
for global
mobility
Anchor Point
for local
mobility
LMAP
Regional
CoA
FHR
FHR
FHR
PoA
PoA
PoA
PoA
AN
MN
On-link CoA1
On-link
CoA2
31
Hierarchical MIPv6 - Remarks

Extension to MIPv6 that allows for local mobility handling


Offers location privacy


Limits the amount of Mobile IPv6 signaling outside the local domain
(signaling between the Mobile Node, its Correspondent Nodes, and its
Home Agent)
Location tracking of a mobile node by its corresponding nodes or its
home agent is difficult because they only know its Regional CoA and not
its on-Link CoA
The local Mobility Anchor Point (MAP) can be located at any
level in a hierarchical network of routers, including the Access
Network Gateway (ANG)
32
Overview of Fast MIPv6
CN
GMAP
HN
ANG
Data between MN and CN
Signaling
Anchor Point
for global
mobility
FHR
PAR
NAR
PoA
PoA
PoA
PoA
AN
New link detected
MN
MN
33
Fast MIPv6 - Remarks




It enables a Mobile Node (MN) to quickly detect that it has
moved to a new subnet by providing the new access point and
the associated subnet prefix information when the MN is still
connected to its current subnet
Aims at minimizing service interruption during handovers by
reducing handover latency and allowing for packet buffering at
network nodes
It allows for transfer of context between network nodes
It allows for network-initiated handovers


The Previous Access Router (PAR) sends an unsolicited router
advertisement message (with information about neighboring links)
Requires cooperation between network nodes


Next Access Router (NAR) and PAR must have a trust relationship
Difficult to be deployed in practice beyond administrative domains
34
Overview of Proxy MIPv6
CN
GMAP
HN
ANG
Data between MN and CN
Signaling
Anchor Point
for global
mobility
Anchor Point
for local
mobility
LMA
MAG
New MN
detected
MAG
PoA
PoA
PoA
Basic IPv6
Signaling
AN
MN
MN
35
Proxy MIPv6 - Remarks

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Doesn’t need Mobile IPv6 functionality in the IPv6 stack of the
mobile node
The proxy mobility agent in the network (MAG) performs the
signaling and does the mobility management on behalf of the
node
The functionality is only supported inside the Proxy MIP
domain. Outside that the MN needs to be mobility-capable
The MN keeps the same address inside the Network-based
Localized Mobility Management (NETLMM) domain for remote
communication with the CN. This results in enhanced location
privacy.
Minimizes signaling overhead in the wireless parts of the
network
36
Trends in Network-layer Mobility Management Protocols

Differentiate between global and local mobility


Add functionality at the network side to support closer-toseamless mobility



Handle mobility in hierarchical manner
Add support for transfer of context (information regarding access
control, QoS profile, header compression for real-time applications, etc.)
between serving and target networks
Provide mobility support for unmodified terminals (network-based
mobility management)
Improve privacy
37
Latencies of Network-layer Handover Solutions

Made up of latencies introduced by link and network layers


Link-layer latencies are due to



Late detection of link state changes
Lengthy scanning and authentication/association procedures
Network-layer latencies are due to




At application level these latencies are cumulative
Late detection of the loss of IP connectivity
Lengthy IP layer parameter configuration process (e.g., address, default router,
DNS, etc.)
Time-consuming address registration updates
Conclusion

Despite of any optimizations in the network-layer procedures, seamless handovers
cannot be experienced unless


Link-layer handover procedures are also optimized
Smooth cooperation between link and network-layer functions is established
38
IEEE 802.21 standard - Approach


Facilitates handover initiation and preparation for vertical
handovers between 3GPP, and IEEE 802.3, 802.11, 802.16
networks
Introduces a common interface to L2. It provides 3 services

The Media Independent Event service


The Media Independent Command service


Events and triggers corresponding to dynamic changes in link characteristics,
status and quality
Commands for the MIH users to control handover relevant link states
The Media Independent Information service

Mostly static network information within a geographical area that can be used
towards efficient handover decisions (dynamic information is obtained
directly from access networks)
39
IEEE 802.21 - Services
Media Independent SAP
Media Dependent SAP
40
IEEE 802.21 MIH Event Service
MIH event
Description
MIH_Link_Detected
Link of a new access network has been detected.
MIH_Link_Up
L2 connection is established and link is available for use.
MIH_Link_Down
L2 connection is broken and link is not available for use.
MIH_Link_Parameters_Report
Link parameters have crossed a specified threshold and need to be
reported.
MIH_Link_Going_Down
Link conditions are degrading and connection loss is imminent.
MIH_Link_Handover_Imminent
L2 handover is imminent based on either the changes in the link
conditions or additional information available in the network.
MIH_Link_Handover_Complete
L2 link handover to a new PoA has been completed.
MIH_Link_PDU_Transmit_Status
Indicate transmission status of a PDU.
41
IEEE 802.21 MIH Command Service
MIH command
Description
MIH_Link_Get_Parameters
Get the status of a link.
MIH_Link_Configure_Thresholds
Configure link parameter thresholds
MIH_Link_Actions
Control the behavior of a set of links
MIH_Net_HO_Candidate_Query
Network initiates handover and sends a list of suggested networks.
MIH_MN_HO_Candidate_Query
MN queries and obtains handover related information for candidate networks.
MIH_N2N_HO_Query_Resources
Sent by the serving to the target MIHF entity to allow for resource query.
MIH_MN_HO_Commit
Used by MN to notify the serving network of the decided target network information.
MIH_Net_HO_Commit
Used by the network to notify the MN of the decided target network information.
MIH_N2N_HO_Commit
Used by a serving network to inform a target network that an MN is about to move.
MIH_MN_HO_Complete
Notification from MIHF of the MN to the target or source MIHF indicating the status
of handover completion.
MIH_N2N_HO_Complete
Notification from either source or target MIHF to the other (i.e., peer) MIHF
indicating the status of the handover completion.
42
IEEE 802.21 MIH Information Service

General Information


Access Network Specific Information


E.g., MAC address, Geographical location, Channel range
PoA Specific Higher Layer Service Information


E.g., Network ID, Roaming Partners, Cost, Network QoS, Network
nominal data rate, Channel range, IP configuration methods, Network
capabilities, Type of mobility management protocol supported
PoA Specific Information


E.g., Network type, Operator ID, Service Provider ID, Country Code
E.g., Supported Subnets, IP address
Other

Vendor specific services
43
SNMP Architecture
SNMP Architecture: An SNMP message passes through the protocol layers at both
the manager and agent. Each layer does a specific communication task.4
Network Discovery - SNMP
45
Port View - SNMP
46
Port View - Graph
47
SNMP Walk
48
OSI Management Architecture
Management
Functions
Managing
Process
CMISE
ACSE
Agent
Process
CMIP
CMISE
FTAM
ROSE
lower
layers
ROP
ROSE
lower
layers
MOs
Things are changing…….
Case: Somebody walking at the street
talking to himself.
 Some years ago: Behavior that probably
needs medical care.
 Today: The most obvious thing - hands free
accessories for mobile phones.

Vision by year 2020
“The improvement of the Individual’s quality of life,
achieved
through the availability of an environment
for
instant provision and access
to
Meaningful, Multi-sensory information and content”
Mediation Bus Introduction

A distributed environment that achieves an
optimized operation of Future Internet (FI)
by performing mediation operations among
the service and network/transport layer
entities that are plugged into it enabling
both service and scenario-oriented enduser treatment by instructing the involved
entities to execute the appropriate
commands in an efficient and network
agnostic way.
Mediation Bus Operations




Translation of policies (rules, constraints and requirements of
the optimized operation of FI) and context view (e.g.,
spectrum, energy status, user profiling, etc.) to executable
transport workflows (functionalities) optimizing the usage of
both computing and network resources
Wrapping functionalities for creation (open APIs) and delivery
(adaptation, orchestration and execution enablers) for
existing and future Internet services
 Searching,
Negotiating,
Reasoning,
Subscribing,
Publishing, security/privacy global capabilities through
appropriate generic enablers/facilitators
Transition path from current application and transport
(TCP/IP) layers deployments to the future Internet one
Vertical control and management functionalities for bus
optimum operation (e.g., for green aware performance) and
self-organization
Mediation Bus Research Trends (4D Approach)
Application
Application Layer (FI)
MB horizontal
position
MB
Transport
Internet
Host-to-Network
Transport
Layer (FI)
A first approach could be to keep
unaffected the application layer of the
current TCP/IP protocol stack, while to
pass some of the existing transport layer
functionalities at the mediation bus in a
more advanced context
The policies actually will constitute the service APIs for
Application Layer (FI)
the communication of the mediation bus with the
application layer, while the workflows will formulate
MB
network APIs for the communication of the mediation
bus with the transport layer. Therefore, the mediation bus MB
Transport
is not simply a layer but a vertical environment that
Layer (FI)
handles also control and management operations
Mediation Bus Research Trends (4D Approach)
Application
Application Layer (FI)
MB
Transport
Internet
Host-to-Network
MB
MB
Transport
Layer (FI)
The backward compatibility with current
TCP/IP protocol stack could be achieved
by putting again the mediation bus
between the existing application and
transport layer.
Since the adaptation of the mediation bus to both
application and transport layers is not going to be
something static but it is going to be heavily affected
by the service, the end user’s context and the
underlying network capabilities, the mediation bus
could be thinned in some cases.
Application Layer (FI)
MB
MB
Transport
Layer (FI)
From today’s Walled Gardens to an Open Internet
with QoS



Keep the lightweight current Internet approach
Plus resource control (implies signaling, access
control and business aspects)
Don’t follow the illusion a Future Internet (FI) could
re-establish an end-to-end connectivity at Layer 3
The FI has to be Resource aware, but Open and Lightweight
Mediation between Services and Transport:
Today‘s Walled Garden Architecture
Walled Garden
Applications with
High Quality
Client
Application
Servers
Network
Services
Network
Services
Application
Servers
Network
Services
Client
Network
Services
IP Network
Infrastructure
Peer
Walled Garden
Service Provider 1
Walled Garden
Service Provider 2
The separation of
Service and Network
is Subject to
De-regulation
Peer
Mediation between Services and Transport:
A Mediation between Applications and Transport
Flexibility for
all Applications
End-to-End
Applications
End-to-End
Applications
Service API
Mediation
Cross Domain Mediation
Cross Layer Service Libraries
Network
Services
Network
Services
Network
Services
Network
Services
IP Network
Infrastructure
Peer
Network Operator
Domain 1
Network Operator
Domain 2
Mediation provides a transparent interface
to enable cross domain access to
cross layer network services
Peer
Mediation between Services and Transport:
Example Use Case: Internet TV
High Definition
Video
Application
Video
Terminal
Video Source
Data & Control Services
Generic Overlay API
Mediation
Open Cross Domain Generic Overlay
Cross Layer Service Libraries
Multi
Casting,
Caching
Extended
Internet
Infrastructure
Peer
QoS
Signaling
Network Operator
Domain 1
Path
Optim.
Authent.
Network Operator
Domain 2
Peer
Summary

Mobility in heterogeneous networks is important for both
operators and end-users.





Mobility management in such environment is a complicated process
Several proposals exist for mobility management at the network
layer in heterogeneous networks (MIP and enhancements)
Exploitation of link-layer intelligence and exchange of
information between mobile node and network is deemed
important
A handover framework built around IEEE 802.21 is promising
towards the delivery of closer-to-seamless experience
There are open research issues regarding, for example, the
interfacing of MIHF to other protocols, the support of DVB,
the transportation of the MIHF messages and the positioning of
the functionality in the evolved 3GPP network architecture
60