Table 1 Difference between WBANs and WSNs[6],[7]
Challenges | Wireless sensor network | Wireless body area network |
|---|---|---|
Scale | Monitored environment (meters/kilometers) | Human body (centimeters/meters) |
Number of nodes | Many redundant nodes for wide area coverage | Fewer, limited in space |
Result accuracy | Large number of nodes provide accuracy | Few nodes, need to be robust andaccurate |
Node tasks | Node performs a dedicated task | Node performs multiple tasks |
Node size | Small is preferred, but not important | Small is essential |
Network topology | Very likely to be fixed or static | More variable due to body movement |
Data rates | Most often homogeneous | Most often heterogeneous |
Node replacement | Performed easily, nodes are even disposable | Replacement of implanted nodes isdifficult |
Node lifetime | Several years or months | Several years or months, smaller battery capacity |
Power supply | Accessible and can be replaced easily and frequently | Inaccessible and difficult to replace in an implantable setting |
Power demand | Likely to be large, energy supply easier | Likely to be lower, energy supply more difficult |
Energy scavenging source | Most likely solar and wind power | Most likely motion (vibration) andthermal (body heat) |
Biocompatibility | Not a consideration in most applications | A must for implants and some external sensors |
Security level | Lower | Higher to protect personal information |
Impact of data loss | Likely to be compensated by redundant nodes | More significant, may require additional measures to ensure QoS and real-time data delivery |
Wireless technology | Bluetooth, ZigBee, GPRS, WLAN, etc. | Low power technology required |
Key management support from application | No | Yes, sensor nodes not required togenerate random numbers |
Human intervention | Not possible in most cases | Possible rather inevitable in some cases |