Transcript TSACC Test Area - 한국정보통신기술협회(TTA)

GSC9/GRSC_026
SOURCE:
TIA
TITLE:
Prime PSO: Ad-Hoc Networking
AGENDA ITEM:
GRSC Item 5.3
CONTACT:
David Thompson, [email protected], +1.703.907.7749/7727 (Fax)
Ad-Hoc Networking
TIA Prime PSO with ETSI inputs
17/07/2015
GSC-9, Seoul
1
Overview of Ad Hoc Networks
17/07/2015
Initial Architectures
- Low power sensors networks
“surveillance” web
- small, relatively static, embedded ad hoc networks
`“bluetooth-type” networks
- Small-to-medium sized, mobile ad hoc networks
“802.11-style”
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Terminlology
Mobile Ad Hoc Networking =
= Mobile, Multi-hop, Wireless Networking
= Mobile Mesh Networking
= Mobile Packet Networking
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Hybrid Communication Networks
Satellite overlay
High-speed
backbone
network
MANET
No fixed infrastructure
Fixed/static infrastructure
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Properties of Ad Hoc Networks
• Allows devices to establish communication, anytime and
anywhere without the aid of a central infrastructure.
• Autonomous, self-organizing terminals
– Unknown number of terminals, may vary
– Topology unknown in advance, may vary
• Distributed routing
– Every terminal is a router
– Information needed for routing is learned adaptively
• Distributed network control
– Admission, security
– Flow control
– Quality of service
Fixed Ad Hoc
Networks
(e.g., “Mesh”)
MOBILITY
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Mobile Ad Hoc
Networks
(MANETs)
Mesh Networks
• Fixed or low-mobility wireless ad hoc networks
– Emphasis on self-configuration in a variety of situations, including failure
of components
– Emphasis on adaptive, distributed network management
IEEE 802.11 ESS Mesh
Example:
Proposed extension to
IEEE 802.11 to specify
means for a wireless ad
hoc formation of a
backbone network of
access points (APs) to
form an ESS
802.11 ESS
(Extended service set)
802.11 BSS (Basic service set)
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Mobile Ad Hoc Networks
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High mobility
Communication over
wireless radio links
Emphasis on rapid deployment of
autonomous mobile users
Decentralized structure
Dynamic topology
Stand-alone or connected to larger
network via gateway
Nodes in network can serve as
routers and hosts
– Can forward packets on behalf
of other nodes and run user
apps.
Contends with effects of radio
communication interference or
congestion
Applicable to PPDR, military,
commercial enterprise, etc.
i.e., MANETs
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Smart Sensor Ad Hoc Networks
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Sensors spread across a
geographical area
– Large number of (mostly
stationary) sensors
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Low energy use
Network self-organization
Collaborative signal processing
Querying ability
Each sensor has wireless
communication capability and
sufficient intelligence for signal
processing and networking of the
data
Node classifications: Individually
addressable, and whether the data
in the network is aggregated
Military, environmental, traffic,
surveillance
– Can assist in the national efforts to
increase alertness to potential
terrorist threats.
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Network Architecture of
Wireless Ad Hoc Networks
• Peer-to-peer: flat architecture, though may organize into “clusters”
for network management purposes
• Adaptable to varying topology and traffic conditions
• Robust: Degrades gracefully in face of node / link failures and local
congestion
• Efficient (bandwidth, power consumption, user capacity) through
multihop communications & spatial reuse
• Possibility of QoS provision
• Scalable
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Mobile Ad Hoc Networking (MANET)
- Dynamic topologies
- Bandwidth-constrained
- Asymmetric links with variable capacity
- Energy constrained
- Multiple technologies can be used simultaneously
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MANET Routing Algorithm Criteria
• Dynamic routing algorithms: Must adapt to
– Entering/departing nodes
– Changes in link quality and terrain
– Traffic patterns and interference
– Rate of topological change
• Fast run time compared to rate of topology change
• Low overhead and storage requirements
• High throughput and low packet delay time
• Preserve network requirements (e.g., security)
• Efficient use of power
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MANET Routing Protocols
(Present or past IETF drafts, some inactive)
• Dynamic Source Routing (DSR)
• Ad Hoc On-Demand Distance Vector (AODV)
• Optimized Link State Routing (OLSR)
• Topology Broadcast based on Reverse-Path Forwarding (TBRPF)
• Zone Routing Protocol (ZRP)
• Temporally-Ordered Routing Algorithm (TORA)
• Landmark Routing Protocol (LANMAR) for Large Scale Ad Hoc
Networks
• Fisheye State Routing Protocol (FSR) for Ad Hoc Networks
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IETF MANET standardization
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MANET - established in 1997 chartered working group within
Internet Engineering Task Force (IETF)
Focussed on studying routing specification with the goal of
supporting network scaling up to hundreds of routers
* Unicast routing protocol
* Multicast routing protocol
Work on routing for large and small scale networks
Work relies on the existing IETF standards such as mobile-IP
and IP addressing
For large-scale MANET the lack of interest has put this work in
question
Flooding: work on requirements had started
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Comment on IETF MANET work
• Early approval constraints due to the accumulation of variant
ad hoc routing protocols and the need to identify a “killer
application.”
• Research now assigned to IRTF (research component of
IETF), and the IETF group is working toward implementable
unicast and multicast protocols in the near term.
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Ad Hoc Routing Protocol Example 1:
the DSR Protocol
• Data packets have source routes stored in their headers. Each
node on the path transmits the packet to the next hop identified
in the source route.
• Each node maintains a Route Cache to store the source routes
it has learned. When a node needs to send a data packet, it
first checks its route cache for a route to the destination. If no
route is found, it attempts to find one using the route discovery
mechanism.
• A monitoring mechanism, called route maintenance, is used in
each operation along a route. This mechanism checks the
validity of each route used.
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Ad Hoc Routing Protocol Example 2:
the AODV Routing Protocol
• Each node maintains a table of hop distances and next-nodes for
different destinations.
• Routes are built on demand using a route request (RREQ)/ route
reply (RREP) query cycle.
• Once the source stops sending data packets, the links will time out
and eventually be deleted from the intermediate node routing
tables.
• If a link breaks while the route is active, the node upstream of the
break propagates a route error (RERR) message to the source
node to inform it of the now unreachable destination(s).
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Example NIST/WCTG MANET Work
Analysis:
• Development of network performance measures, standard evaluation
scenarios, analysis of multihop network properties and performance
Simulation:
• OPNET simulation/evaluation of multihop routing protocols, “costadaptive mechanisms” for choosing paths
Embedded Implementation:
• Development of Linux kernel implementation of AODV
• Development and testing of communication and localization system
prototype based on ad hoc networking
URL: http://w3.antd.nist.gov/wctg/manet/
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NIST Distributed Testbed for First Responders
• Hardware:
– Compaq iPAQs running Linux, dual
PCMCIA card backpack with battery,
802.11b cards, full-duplex audio.
• Capabilities:
– Multihop packetized voice: broadcast,
multicast, unicast; group IDs, etc.
Packets include terminal sensor data.
– Indoor localization: 1 to 3 m using
signal strengths; display of terminal
locations.
– External communication: Interface to
external networks using Session
Initiation Protocol.
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Emerging Applications of Ad Hoc Networking
• Mesh applications may be becoming popular alternatives to building new
wired infrastructure
• Commercial/personal ad hoc networking capabilities
– Including Peer-to-peer
• Emerging sensor networks
• Ad hoc principles are proposed to enable multihop extensions of
WLAN/RLAN structures
• Complete solutions are needed before the special features of ad hoc
networking may be considered advantageous
– i.e., network management, distributed database, VoIP, capacity for multimedia,
etc.—these solutions are emerging as different types of wireless systems
converge
• IEEE, ITU-R and other standards bodies have existing and initiated
evolutions to existing standards that may be beneficial to ad hoc
networking applications (including security, RLAN, etc.)
• Other standards activity:
– Project MESA (part of proposed PPDR capabilities)
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Ad Hoc Network Applicability
Scale
Network type
Commercial
Small scale
(few nodes)
Large scale
(many nodes)
home/office personal
industrial local
networks
mobile cellular like
Government specific Public Safety
Community/urban
networks
“covert” networks
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Large-scale military
network
local communications
Ad Hoc Networking
• Lack of specific network layer standards for Ad Hoc
networking.
• Note the term "ad hoc" can also be used in a more general
sense, applying to networking modes involving Bluetooth-like
abilities and other WPANs as well as use of 802.11 as the
radio protocol.
• Need for GSC/GRSC Resolution?
– Clarify and focus subject
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Open issues
A
optimisation network layer and radio layers for different systems
(incl. 802.11, HiperLAN)
B
QoS support
C
secuirity
D
mobility
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B, C, D issues could be orthogonal, joint optimization is very
difficult (system design choice)
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tradeoff between centralized and distributed algorithms for
B,C,D
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Relevant ETSI activities
• MESA Project - ad hoc network on future Public Safety
communications
• BRAN - HiperLAN-2, other
• 3GPP - UTRA TDD
Standardization challenges =>
There is need for standard-based approach at the network
layer.
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Ad Hoc Networking
Thank You!
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