Pervasive Computing Devices

Device Technology for Pervasive Computing include Power-provisioning technologies, Display technologies, Memory technologies, Communication technologies, Processor technologies, Interfacing technologies, Sensor Technologies and Authentication Technologies.

Technology Aspects

Low-power Device Technologies 

Since many of the devices involved in the pervasive computing environment may have to be small in size and may have to live on their battery / power units, consumption of lower power, extension of power provisioning period etc. assume critical significance. In addition, prevention from excessive heating also requires attention. Power requirements can be reduced by several means right from material selection and chip-level designing to software designing and communication system designing. Power provisioning technology including the Battery design technology plays a very important role in the process.

Batteries as Power Provisioning Devices 

•Key issue: Size and weight of the batteries versus the power capacity and price 

•Bottleneck: Relatively slower advances in the battery technology compared to those in other fields like display and storage technologies 

•Major choices available: Nickel-Cadmium (NiCd: 12-27 hrs. standby time), Nickel-Metal-Hydride (NiMH: 16-37 hrs. standby time), Lithium- Ion (Li-ion:21-50 hrs. standby time), Lithium-Polymer Cell based batteries (> 60 hrs. standby time, flexible shapes) etc.

Display Device Technologies Not all pervasive computing devices need display elements but those needing them may have a range of different requirements in terms of: 

–Display-size 

–Display-shape 

–Display-resolution 

–Display-colour richness

–Display viewing angles to be supported 

–Display power provisioning constraints 

–Display refresh rates etc.

Major Display Device Technologies 

•Cathode Ray Tube based Displays (CRTs) 

•Liquid Crystal Displays (LCDs) Active Matrix Displays 

§Thin Film Transistor Displays (TFTs) Passive Matrix displays 

§Single Scan Displays (Colour Super-Twist Nematic: CSTNs) 

§Dual Scan Displays (Dual Super-Twist Nematic: DSTN) 

§High-Performance Addressing displays (HPAs)

•Light Emitting Diode based Displays (LEDs) 

o Organic LED based Displays (OLEDs) 

•Light-Emitting Polymer based Displays (LEPs) 

•Chip-on-Glass Displays (CoGs) 

•Liquid Crystal on Glass Displays (LCoGs)