Power aware computing and context aware computing

Q.2) Explain in detail the Power aware computing and context aware computing with suitable example.

Ans.

Power aware computing
The main goal of power aware computing is to conserve energy for routing messages from source to destination. The current era is world of wireless network where the nodes communicate with each other in multi hop fashion. There are different data transmission protocol are used in this technology. Different routing methods will consume more battery power. Power aware routing metrics has provided important role in power aware computing.

There are two types of traffic considered under power aware computing.

- Unicast: Data packets are travels towards single receiver.
- Broadcast: Data packets are travels towards several network nodes.

In unicast, with respect to power consumption there are five Different Routing metrics defined.

- Energy Consumed By one packet.
- Time for Network partition.
- Variance in power level across mobiles
- Cost for one packet
- Maximum mobile cost

To save energy, it is important to minimize all metrics except the time parameter and it has to maximize.

- Power Aware Computing Methods.
- Data caching: Data are cached at mobile device.
- Cache invalidation mechanism: If the data is invalid due to expiry date or modification, then server notify to all the client devices about data invalidation.
- Normalization of records: Before transmitting the data, the records should be normalized as example Duplicate records should be suppressed and not transmitted.
- Protocol optimization

Context aware computing

Context-aware computing or pervasive computing is a mobile computing mechanism in which software applications can discover and take advantage of contextual information such as user location, time of day, nearby users, devices, and user activity.

Some other definitions are:

What it is…

Context-aware computing is:
“software that examines and reacts to an individual’s changing context.”
By- Schilit, Adams, & Want 1994

“aware of its user’s state and surroundings , and help it adaptits behavior”
By- Satyanarayanan 2000
What is context?

“any information that can be used to characterize the situation of an entity.”
(Dey et al., 2000)

Classification of context
- Identity (Who)
- Activity (What)
- Time (When)
- Location (Where)

Application of context

Dey proposes three basic functions that should be implemented by any context-aware application.

- Presentation of information and services.
Presentation of information and services means that either it present context information to the user, or use context help the user for selections of actions.

Examples: According to the context, it provides the user’s location on the map and nearby sites of interest.

- Automatic execution of services.

Examples: A navigation system that provides you direction when the user misses a turn.

- Storage (and retrieval) of context information.

Example: A context aware system that provides the data related to meeting as who was there, when the meeting occurred and where it was located.

Context-aware applications

- Context-aware browser (CAB)
- Context-based workplace awareness
- ConaMSN: A context-aware messenger
- InCarMusic: Context-aware music recommendations
- HEP: Context-aware communication service provision

Security and privacy issues

There are two main security concerns with context-aware systems.

- Ensuring privacy of location and identity information.
- Ensuring secure communications.