Wireless Body Area Network (WBAN) is used for communication among sensor nodes operating on, in or around the human body in order to monitor vital body parameters and movements. A typical sensor node in WBAN should ensure accurate sensing of the signal from the body, carry out low-level processing of the sensor signal, and wirelessly transmit the processed signal to a local processing unit. One of the main limitations of the WBAN radio receiver at Imec-Holst Centre, is its poor performance in the presence of excessive interference in the unlicensed 2.4 GHz Industrial Scientific and Medical (ISM) band. Several WLAN, bluetooth and Zigbee devices are expected to operate in the same band, causing interference to the WBAN system. The ability to tolerate the presence of unacceptable interference in this band is crucial in order to minimize the energy consumption of the WBAN system. By designing suitable spectrum sensing algorithms using network cooperation, all the available spectral holes (white spaces) in this band can be obtained accurately and efficiently, thereby improving interference tolerance level of the WBAN system. This thesis work focuses on developing energy detection based cooperative spectrum sensing algorithms, that would enhance the interference tolerance capability of WBAN system in the unlicensed 2.4 GHz ISM band. The available spectral holes in this band are expected to be accurately and efficiently obtained by introducing adaptive scheduling techniques in these spectrum sensing algorithms. The challenge lies in designing these algorithms when considering multiple interferer's in the unlicensed 2.4 GHz ISM band, since numerous devices of different applications are expected to be operating in close proximity, using the same band. The proposed algorithms are investigated and compared with respect to various sensing parameters including accuracy, efficiency, energy and complexity.