## 5 Conclusions  
Global routing using [PERSON]'s algorithm was augmented with a novel cost function specialized for balancing energy consumption at the nodes and increasing NL in WBANs. The cost function was designed to avoid relaying through nodes which spent more accumulated energy than others. As a result, each node's link costs are dynamically changed to balance energy use in the network. The algorithm was evaluated through real-time implementation in dynamic indoor environments and computer simulations using real channel RSSI data. Two network architectures were evaluated: on-body AP and off-body AP with multiple antennas. Results for the on-body AP network architecture depicted efficient balancing of energy consumption across nodes in the network and an average increase in NL of 40%. The corresponding average increase in EpB was a moderate 0.4 dB. Results for the off-body AP network architecture depicted an increase in NL of 25%, 22%, 20% and 16% for one, two, three and four antennas, respectively. The increase in EpB across all configurations was a marginal 0.025 dB.  
Network connectivity analysis revealed a threshold effect. It was shown for all network architectures that if the ratio between maximum transmitted power and target RSSI is higher than about 65 dB, then [PERSON]'s algorithm results in full connectivity almost all the time. If the ratio is  
\begin{table}
\begin{tabular}{p{113.8 pt}|p{113.8 pt}|p{113.8 pt}} \hline
**Technique** & **Parameter** & **Performance Improvement** \\ \hline Use of dedicated relays [3] & Energy consumption in sensor nodes. & Decreased by a factor of 20. \\ \hline  & BER & Slight improvement in BER. \\ Opportunistic Routing [4] & Energy per bit & 25\% less than Multi-hop routing. \\  & Network lifetime & Increases somewhat. \\ \hline Transmit Power Adaptation [5] & Energy per bit & Power control reduces energy per bit. \\ \hline Minimum Energy Packet Forwarding Protocol [6] & Energy per bit & A 10\% reduction due to power control and a 1.7\% reduction due to ARR. \\ \hline
**Proposed Modified [PERSON]’s Global Routing Algorithm** & Network lifetime & Up to 40\% increase. \\  & Energy per bit & A slight increase. \\ \hline \end{tabular}
\end{table}
Table 2: Summary of WBAN routing algorithms performance.  
below the threshold, network connectivity is severely hindered. This result holds for any link cost function being used.  
The proposed global routing approach allows WBANs to operate efficiently for longer periods of time before recharging of batteries is required. Due to the balancing of energy use in the network, devices would deplete their energy sources at approximately the same time. This is highly beneficial since all devices can be recharged or replaced simultaneously, instead of constantly monitoring and servicing individual devices. Since NL is increased as well, depletion of batteries is less frequent, decreasing maintenance requirements even further. The moderate increase in EpB indicates that the wearability of the WBAN is unhindered.  
In its current form, the protocol is optimizing energy use solely with regard to the transmission power required to transverse the wireless link. A future modification could make use of actual battery status in the algorithm. This would allow devices with different power sources and power requirements to be addressed in the energy balancing process.