SELFORGANISATION

1
SELF-ORGANISATION

• SWATHI

2
INTODUCTION

• The spread of the Internet, mobile
  communications, and the change of traditional
  market models result in the whole information
  infrastructure operating as a global dynamic
  system.
• New maintenance requirements have to be met, for
  example software that cannot be stopped must
  evolve to meet changing requirements
• We need the system to be able to adapt to
  constant failures and replacement of agents and
  changes in the environment, without human
  intervention.

3
Unstructured Wireless Networks

• Each node has a wireless transceiver
• Every node can forward packets
• Nodes associate in an Ad Hoc manner to form a
  network
• need to self organize to form a network
• multiple access wireless communication
• Certain periphery nodes may be linked to the
  wired network

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Self-Organization

• A self-organized network is an independent
  collection of nodes in which enough information
  or the ability to retrieve such information is
  present in order to allow transfer of information
  between any two nodes in the network.
• Either at initialization or after a
  topology-modifying event
• Level can vary depending on the network
  considered.

5
Cont

• Self-organizing applications (SOAs)
• Self-organizing behavior is often the result of
  the execution of a number of individual
  application components that locally interact with
  each other aiming to achieve their local goals
• By self organizing artifacts we mean a setup
  where different devices, with different
  fabrications and functionalities can communicate
  and integrate information to produce novel
  functionalities that the devices themselves could
  not achieve

6
Cont..

• Self organizing integration can be divided into 3
  sub problems
• Devices should learn to communicate with each
  other, even when they have no a priori shared
  understanding of what a particular message or
  function means
• Devices should learn which other devices they can
  trust to cooperate, avoiding the others.
• Devices should develop an efficient division of
  labor and work?ow, so that each performs that
  part of the overall task that it is most
  competent at, at the right moment, while
  delegating the remaining functions to the others.

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Spectrum of self-organization
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ISSUE To increase capacity of cellular networks
using self-organization

• Major shift from voice to data rate services
• One way is to move towards smaller cells ,which
  makes planning process more difficult and
  expensive.
• Self-organization is an emerging principle in
  which we can organize future cellular networks.
• For the success of future services the cellular
  networks should be more self organizing such that
  they could be made more intelligent and situation
  aware.

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Classification of self organizing technologies
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Ways of handling excess traffic

• The cell could borrow resources, bandwidth or
  hardware, from a neighboring cell.
• It could also make a service handover request to
  a neighbor in order to minimize the congestion.
• Thirdly, a service handover request could be made
  to a cell in a layer above or below in the
  hierarchical cell structure.
• Finally, the cell could try to reduce the path
  loss to the mobile
• terminal to minimize the impact of other cell
  interference.

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Cont..

• If neighboring cells are unable to assist the
  congested cell, the options left for the cell are
  to degrade the users service quality or to try
  and influence the users behavior.
• Service pricing strategies
• The pricing scheme can be regarded as a
  protection mechanism for the network.
• Self-organizing technologies must fit into one of
  these categories.

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Multitier scenario where numerous self organizing
technologies potentially could be applied
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Self organizing technologies

• Bunching of base stations
• Dynamic charging
• Maximum revenue method
• Power control method
• Intelligent relaying
• Situation awareness
• Dynamic cell sizing
• Radio resource management
• Intelligent handover

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Bunching of base stations

• Number of transceivers always limits base station
  capacity, even if from an interference point of
  view it could support more users
• A novel bunch concept, consisting of a central
  unit and remote antenna units, has been proposed
  for UMTS
• Highly complex environment will require advanced
  radio resource management (RRM) algorithms and it
  will be beneficial to have a central intelligent
  unit that can maximize the resource utilization.

15
Cont.

• It involves a central unit (CU) that controls a
  set of remote antennas and base stations.
• CU will have complete control over all traffic in
  its coverage area and will be able to maximize
  resource utilization for the current traffic.
• All remote antenna units within a bunch will be
  frame and timeslot synchronised

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UMTS scenario with mixed cell structure
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Cont

• For hot-spot configuration CU may be in area
  covered by RAU.
• For building coverage CU could potentially be
  located on the site where RNC is situated.
• Main benefits of bunching base stations is the
  flexibility and capacity it provides
• This flexibility ensures a high utilization of
  the hardware, whilst ensuring that capacity
  fluctuations anywhere in the network can be
  accommodated without unnecessary infrastructure.

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Intelligent relaying

• It is a technique that can minimize the number of
  base stations and amount of planning in a
  cellular network
• A relay-enabled mobile need only transmit
  sufficient power to transmit data to the next
  mobile in the transmission chain, hence leading
  to an overall reduction in the power needed
  across the network.
• Intelligent relaying can be implemented in both
  indoor and outdoor environments

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Intelligent relaying in an urban macrocell
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An intelligent relaying overlay
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Cont..

• To plan a network incorporating intelligent
  relaying, we consider each mobile as a virtual
  cell
• The mobile will set the radius of its virtual
  cell according to the number of other mobiles in
  the vicinity available to relay data the size of
  the virtual cell will be minimized to improve
  frequency reuse.
• Intelligent relaying can therefore be considered
  as a self organizing enhancement to regular
  cellular network

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Situation awareness

• In current cellular systems base stations
  transmit information on their broadcast control
  channel, which can be used to implement situation
  awareness
• Assume the information includes
  Iidx_laty_longTx
• This enables the network to reconfigure its base
  station coverage areas when a base station is
  removed or added to the network
• It will improve the quality of service when a
  base station fails, as it enables neighboring
  base stations to try to cover the resulting
  coverage gap.

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Environment adaptation scenario a new base
station has been inserted
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Cont

• The base stations can monitor each others
  performance and take appropriate action to adapt
  to the current changes
• The surrounding base stations detect this and
  adapt their coverage areas accordingly to
  accommodate the new cell.
• Situation awareness will be the backbone concept
  in self organization

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Dynamic cell sizing

• Hierarchical cell structures were developed so
  that both the coverage and the capacity
  requirements could be met in a cost-effective
  manner.
• Larger cells provide good coverage, smaller cells
  provide high capacity.
• By dynamically adjusting the coverage areas of
  the cells optimum network performance can be
  achieved under any traffic conditions

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Cell radius reduction

• Decreasing the cell radius
• from 500 to 200 m a capacity
• increase of 33 is achieved for
• voice services

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Intelligent handover

• Current handover strategies only consider
  parameters such as mobile speed and service type
  when choosing which cell should be allocated to a
  user.
• Intelligent handover techniques also consider
  parameters such as resource utilization.
• IH algorithms should enable seamless handover
  between networks providing a different quality of
  service.

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Intelligent handover network adaptation in real
time
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Capacity gain from the self organized technologies

• Because of the inherent flexibility in the bunch,
  the transceivers can be utilized l00, unlike in
  a GSM network where an unacceptable blocking
  probability is reached in uniform traffic at 60
  loading.
• Distributed antennas provide a substantial
  capacity gain because of the lowered transmit
  power and hence reduced interference level

30
Cont

• Maximum capacity gains for three combined
  technologies is shown in figure

31
Cont

• A maximum capacity increment of 13 times was
  estimated for a microcellular network.
• The biggest improvement the self-organizing
  concept brings with it is the almost two orders
  of magnitude improvement in flexibility,
  something which will improve the perceived
  quality of service substantially

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ISSUE-2 To dynamically reorganize mobile
applications using self organization

• Mobile applications are typically hosted in
  resource-constrained environments and may have to
  dynamically reorganize in response to changes of
  user needs, to heterogeneity and connectivity
  challenges, as well as to changes in the
  execution context and physical environment.
• Solution for this problem is to use self
  organization in physically mobile applications.
• A component model , SATIN that incorporates code
  mobility primitives , assists in building self
  organizing mobile applications

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Cont

• Mobile computers are exposed to a highly dynamic
  context and can connect to information on
  different networks through wireless links.
• The current state-of-practice for developing
  software for mobile systems offers little
  flexibility to accommodate such heterogeneity and
  variation.
• More flexible solutions are required that empower
  applications to automatically adapt to changes in
  the environment and to the users needs.
• self organizing system is such a system which is
  able to adapt to accommodate changes to its
  requirements.

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Advantage of self organization in mobile
applications

• Deploying applications (ring tones games) to
  mobile phones.
• .

• Deploying maintaining applications from peers
• .

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Logical mobility and component model in
self-organization

• Self organizing system largely focuses on the
  application of genetic algorithms, expert and
  agent based systems which are tend to be heavy
  weight and appear unsuitable for mobile
  applications.
• Therefore here we use logical mobility and
  components to offer self organization to mobile
  systems.

36
Cont

• Logical Mobility is defined as the ability to
  ship part of an application or even to migrate a
  complete process from one host to another.
• Component Models, argue for the decoupling of a
  system into a set of interacting components with
  well defined interfaces.
• SATIN , a lightweight component model that uses
  logical mobility to offer self organization.

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Advantages of component based approach using
logical mobility

• Representation of applications as interoperable
  components allows for updating individual parts.
• Componentisation promotes code reusability,
  preserving the limited resources of mobile
  devices.
• Logical mobility primitives allow for
  transferring components existing in any host that
  is in reach, in a peer to peer fashion. This
  makes application installation and updating
  easier.
• A component model can provide higher level
  interaction and communication primitives between
  components, located either on the same or on
  different hosts.

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SATIN

• SATIN , component model supports the cloning and
  migration of components between hosts, providing
  for system autonomy when network connectivity is
  missing or is unreliable.
• SATIN component encapsulates particular
  functionality.
• SATIN components separate interfaces and
  implementations.
• The SATIN component model does not support
  abstract components

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Component SATIN metamodel
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SATIN scripting framework

• BeanShell , an open source Java source
  interpreter and scripting mechanism as a SATIN
  component.
• Using this they have created a shell for SATIN,
  which allows developers to manipulate the
  container and its contents by typing Java
  statements at runtime.
• The SATIN shell demonstrates how a library is
  added into the system, promoting reusability
  between components.

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SATIN shell
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ISSUE-3 Distributed Resource Sharing using
Self-Organized Peer-to-Peer Networks

• Distributed resource sharing in the web can be
  solved effectively and efficiently through self
  organization techniques
• The architecture we envision supports both query
  and publish/subscribe functionality using
  languages from Information Retrieval.
• Two functionalities for the architecture
• One-time querying
• Publish/subscribe (pub/sub)

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Architecture for distributed resource sharing
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Functionalities of architecture

• One-time querying A user utilizes his client to
  pose a query (e.g., I want papers on self
  organization) and the system returns a list of
  pointers to matching resources owned by other
  clients in the network.
• Publish/subscribe (pub/sub) In a pub/sub
  scenario, a user posts a continuous query to the
  system to receive a notification whenever certain
  events of interest take place (e.g., when a paper
  on self-organization becomes available).

45

• Two kinds of nodes in architecture
• Super-peers
• Clients
• Data model AWP inspired from Information
  Retrieval for specifying queries and resource
  metadata
• Publication is a set of attribute value pairs (A
  , s) where A is a named attribute, s is a text
  value and all attributes are distinct.

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Example of publication

• (AUTHOR John Smith),
• (TITLE Information dissemination in P2P
  systems)
• (ABSTRACT In this paper we show that )
• The query language of AWP offers Boolean and
  word proximity operators on attribute values
• Example of a conjunctive AWP query
• AUTHOR John Smith
• TITLE w p2p (information Á00
  dissemination)

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DHTrie protocols

• DHTrie protocols
• Three levels of indexing to store continuous
  queries submitted by clients.
• The first level corresponds to the partitioning
  of the global query index to different
  super-peers using DHTs as the underlying
  infrastructure.

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Cont

• The DHT infrastructure is used to define the
  mapping scheme and also manages the routing of
  messages between different super-peers.
• In the second level each super peer uses a hash
  table to index the attributes contained in a
  query
• In the third level a trie like structure that
  exploits common words in atomic queries is
  utilized.

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Self-organization in the chord ring

• Chord-like DHT is used to implement our
  super-peer network.
• Chord uses consistent hashing to map keys to
  nodes.
• Each node and data item is assigned an k-bit
  identifier
• Identifiers can be thought of as being placed on
  a circle from 0 to 2k - 1, called the identifier
  circle or Chord ring.

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Chord ring
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Self organization of data items and nodes in
chord ring

• A new data item r is stored at the node with
  identifier H(r) if this node exists, given that H
  is the hash function used. Alternatively, r is
  stored at the node whose identifier is the first
  identifier clockwise in the Chord ring starting
  from H(r). This node is called the successor of
  node H(r) and is denoted by successor (H(r)).
• Self stabilisation protocol

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Subscribing with a continuous query

• C submits a continuous query q of form
• A1 S1 Am Sm Am1 WPm1
  An WPn
• C contacts a super-peer S (its access point) and
  sends it a message SubmitCQuery(id(C) , q)
• When S receives q, it selects a random attribute
  Ai, 1 lt i ltn contained in q and a random word Wj
  from text value Si or word pattern WPi

53
Cont

• S forms the concatenation AiWj of strings Ai and
  Wj and computes H(Aiwj) to obtain a super peer
  identifier.
• S creates message Fwd-CQuery(id(S) id(q) q) and
  forwards it to super peer with identifier H(AiWj)
  using the routing infrastructure of the DHT.
• When a super-peer receives a message FwdCQuery
  containing q, it inserts q in its local data
  structures using the insertion algorithm

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Publishing a source

• When client C wants to publish a resource, it
  constructs a publication p of the form (A1,s1),
  (A2 , s2),.., (An , sn), it contacts a
  super-peer S and sends S a message
  PubRe-source(id(C) p)
• For every attribute Ai, 1 lt i lt n in p, and every
  word wj in si, S computes H(Aiwj) to obtain a
  list of super-peer identifiers
• S then sorts this list in ascending order
  starting from id(S) to obtain list L and creates
  a message FwdResource(id(S), id(p), p,L) and
  sends it to super-peer with identifier equal
  head(L).

55
Cont

• Upon reception of a message FwdResource by a
  super-peer S, head(L) is checked. If id(S)
  head(L) then S removes head(L) from list L and
  makes a copy of the message.
• The publication part of this message is then
  matched with the super peers local query
  database and subscribers are notified
• Finally, S forwards the message to super peer
  with identifier head(L). If id(S) is not in L,
  then it just forwards the message

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Notification to interested subscribers

• When a message FwdResource containing a
  publication p of a resource arrives at a
  super-peer S, the continuous queries matching p
  are found by utilizing its local index
  structures.
• Once all the matching queries have been retrieved
  from the database, S creates a notification
  message of the form CQNotification(id(C), l(r),
  L, T).
• Upon arrival of a message CQNotification at a
  super-peer S, head(L) is checked to find out
  whether S is an intended recipient of the
  message.

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Cont..

• If head(L) id(S), then S scans T to find the
  set U of query identifiers that belong to clients
  that have S as their access point, by utilising a
  hash table that associates query identifiers with
  client identifiers.
• For each distinct query identifier in set U, a
  message MatchingResource(id(S) id(q) l(r)) is
  created and forwarded to the appropriate client.

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conclusion

• Self-organization enables spontaneous, autonomous
  networks among mobile devices, and also helps
  conventional network operators reduce the
  administrative need and complexity in network
  installation, maintenance, and management.
• Introduction of self-organized functions has the
  potential to reduce costs and improve the
  robustness of the network.
• Self organization is also about giving up control
  over the network and letting it organize itself
  as much as possible.

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References

• Introduction
• http//esoa.unige.ch/esoa05/esoa05-cfp.html
• http//www.winlab.rutgers.edu/pub/docs/focus/4G-Zh
  ao1.pdf
• http//www.winlab.rutgers.edu/pub/docs/focus/4G-Ra
  ju.pdf
• http//www.cs.unt.edu/rdantu/SPRING_2006_ADVANCED
  _WIRELESS/SelfOrganizedCellularNetworks.pdf
• http//pespmc1.vub.ac.be/Papers/SO-Artifacts.pdf
• ISSUE1
• http//ieeexplore.ieee.org/iel5/2219/18489/008507
  69.pdf?tparnumber850769isnumber18489

60

• http//libproxy.library.unt.edu2133/iel4/5930/15
  794/00734341.pdf?tparnumber734341isnumber1579
  4
• http//libproxy.library.unt.edu2133/iel5/35/3152
  3/01470824.pdf?tparnumber1470824isnumber31523
  
• Issue-2
• http//www.cs.ucl.ac.uk/staff/S.Zachariadis/p
  apers/doa04.pdf
• http//libproxy.library.unt.edu2133/iel5/35/3152
  3/01470824.pdf?tparnumber1470824isnumber31523
  
• ISSUE-3
• http//www.cs.unibo.it/self-star/papers/koubar
  akis.pdf
• http//csdl2.computer.org/comp/proceedings/p2p
  /2003/2023/00/20230212.pdf