Title: Survivable Mobile Wireless Networks: Issues, Challenges, and Research Directions
1Survivable Mobile Wireless Networks Issues,
Challenges, and Research Directions
- Regina Rosales Hain, Alden W.Jackson, David
Levin, Ram Ramanathan, and John Zao BBN
Technologies
WiSe02, Sept. 28, 2002, Atlanta, Georgia, USA.
Presented by Derek K.D. Jiang
2Outline
- Introduction
- Definition of Survivability
- Survivable connectivity
- Survivable communication
- Survivable technologies
- Conclusion
3Introduction
- This paper is a survey of the issues, challenges,
and proposed research direction in survivable
mobile wireless network. - Survivability consists not only of robustness
against natural faults or misconfigurations, but
also failures induced by malicious adversaries.
4Introduction
Definition of Survivability
Introduces and defines survivable networking and
its aspects.
Survivable Connectivity
Discusses establishing and maintaining network
connectivity.
Argues that we should expect a challenging mobile
wireless communication environment.
Survivable Communication
Survivable Technologies
Discusses adaptive networking
5Definition of Survivability
- Traditional security research
- Primarily focused on the protection from attacks
other than continued correct operation under
attacks. - Faults are assumed to be independent and random.
- Survivability research
- The presence of intelligent adversarial attacks
significantly challenge the conventional models. - Software and protocol vulnerability become more
important considerations.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
6Definition of Survivability
- The definition we use here is from Software
Engineering Institute - 1. Survivability is the capability of a system to
fulfill its mission in a timely manner, even in
the presence of attacks or failures. - 2. The focus of survivability is on delivery of
essential services and preservation of essential
assets. - 3. Survivability depends on four key
capabilities, the four Rs resistance,
recognition, recovery, and refinement.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
7Military Network Survivability
- Using wireless networking technologies to support
military operations imposes survivability on - 1. Transmission Security (TRANSEC) - the
protection at physical, medium access and data
link layers from radio signal detection, jamming,
control/user data acquisition, and eavesdropping. - 2. Communication Security (COMSEC) - the
protection of data to achieve CIA,
non-repudiation, anti-replay, traffic analysis
countermeasures.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
8Military Network Survivability
- Using wireless networking technologies to support
military operations imposes survivability on - 3. Authorization and Access Control - the support
of multi-level security measures by implementing
identity or role based access control. - 4. Network Infrastructure Protection - the
protection of network management infrastructure
from both passive and active attacks, rogue AP,
illegal access to message. - 5. Robustness and efficiency.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
9Cellular Network Survivability
- Focused primarily on infrastructure survivability
other than malicious attacks. - Vulnerability
- Network upgrade, especially involving software.
- Rapid evolution leads to learning-curve problem.
- Single point of failure.
- Poor management tool.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
10Low Probability of Detection
- For most military ad hoc networks the ability to
low probability of detection, interception, and
exploitation (LPD/LPI/LPE) is of paramount
importance. - Survivability is enhanced when the network is
stealthy to potential adversaries. - The tradeoff of lower transmission power between
adversaries and legitimate users.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
11Survivable topological connectivity
- Reducing transmission power limits the range of
inter-node links used for multi-hop routing and
also increasing the probability of the network
becoming partitioned. - How can we reduce power while maintaining desired
connectivity?
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
12Survivable topological connectivity
- We must adaptively adjust transmit powers of
nodes in response to mobility. - Research optimize certain power metrics while
adhering to certain connectivity constrains. - Power metrics
- minimize the maximum (or average) power used by
the network. - Maximum power and average power.
- Connectivity constrains
- Tradeoff between robust connectivity and LPD.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
13Survivable communication
- Some situations where the environment is so
challenging that ideal connectivity is
impossible. - Channel condition (noise or jamming)
- High mobility
- We should expect and exploit those conditions
- Asymmetric links
- Weak connectivity
- Episodic connectivity
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
14Asymmetric channel connectivity
- Several ad hoc routing protocol expressly
prohibit unidirectional routing based on the
performance consideration. - In tactical network may require the use of
asymmetric and unidirectional links - Secrete information in radio-silent mode.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
15Unstable end-to-end paths
- The eventual stability model of ad hoc routing
assumes that routing converges eventually after
partitioning.
Under this model, a complete path to destination
must exist at a given time.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
16Unstable end-to-end paths
- This model is used by on-demand routing as well
as table-driven protocols. - Challenges to this model
- Range limitations imposed by LPI/LPD concerns.
- Intermittent and/or targeted jamming can disrupt
routing converge. - High mobility is another aspect.
- Ad hoc routing protocols can be categorized into
three - Table-driven (Proactive), ex. CSGR, WRP
- On-demand (Reactive), ex. DSR, ADOV
- Hybrid, ex. ZRP
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
17Unstable end-to-end paths
- The eventual connectivity model relaxes the
traditional assumptions so that communication can
proceed along partial segments of paths between
communicating nodes. - There is no need to require that a complete
physical path between communicating processes
exist.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
18Unstable end-to-end paths
- Information progresses as far as possible, along
whatever paths possible, until it reaches its
destination.
Make use of the concept of store-and-forward, and
require modifying the typical forwarding behavior
of dropping packets.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
19Unstable end-to-end paths
- This requires changes to current forwarding
mechanisms. - The unavailable link should be marked in a new
field in the forwarding table. - Requiring additional buffers at nodes to store
packets and algorithms to determine which data is
dropped when the buffers are full - Support multiple routing approaches at the same
node to switch these two modes.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
20Nomadicity V.S. Mobility
- Mobility
- Tries to maintain active sessions.
- Continuous access to preconfigured infrastructure
is assumed. - Nomadicity
- Assumes constant movement.
- Anticipates disconnected operation as the norm.
- Applications are expected to tolerate
disconnection during movement.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
21Nomadicity V.S. Mobility
- Addressing problem in both aspects
- The address is assigned once and held as long as
possible, or the node acquire a new address when
moving to a different subnetwork. - Issue
- When multiple addresses are available, the issue
lies in whether we can seamlessly and securely
migrate sessions when readdressing due to
mobility.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
22Routing under high mobility
- In the case where mobility is highly frequent, it
is necessary to use knowledge of the location and
trajectories of nodes to predict future location. - Trajectory routing uses trajectories to compute
destination node locations.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
23Routing under high mobility
- When the trajectory is not deterministic, the
need for current location can be mitigated by
multicast spraying of information into a region
that the node can be expected with high
probability.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
24Exploiting mobility to achieve connectivity
- It is possible to exploit mobility to communicate
by means of the two ways below. - Movement control can be used to exert control on
other nodes into the range that a path toward the
destination exists. - Mobile node can store-and-haul packets toward
their destination by physically transporting the
data.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
25Adaptive and agile networking
- Some technology centric thrusts to adapt to
dynamic environments and to achieve connectivity. - Topological versus Geographical routing
- Geographical routing techniques have proposed for
wireless and sensor networks. - No routing-table, no overhead to find or update
routes - Position required, Determining position via
external service, and internal search-process. - Static wired infrastructure tends to be better
suited to topological approaches. - Survivable nodes must support both strategies.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
26Adaptive and agile networking
- Adaptive nodes and networks can be achieved by
active networking technology. - The application of the technology to mobile
wireless networking allows - Dynamic selection of MAC and network layer
parameters - The ability to dynamically provision and
negotiate algorithms and select entire protocols
based application requirement and the
communication environment.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
27Adaptive and agile networking
- Advantages of active networking
- Eliminate the need to standardize the entire
protocols and algorithms. - Need not hard-code them into nodes.
- Only a framework for node discovery and protocol
negotiation need to be pre-determined.
Definition of Survivability
Survivable Connectivity
Survivable Technologies
Survivable Communication
28Conclusion
- Significant progress has been made toward
survivable network, however, further work needs
to be done to understand the tradeoffs against
stealth requirement (LPI/LPD/LPE). - Challenge channel condition should be regarded as
a norm, similarly, mobility must be expected and
exploited to enhance survivability. - Since it is impossible to predict the
communication environment, it is critical that
network nodes and protocols can adapt to the
variation.
29- Thanks for your listening