**Author details**

Elias Yaacoub and Adnan Abu-Dayya *QU Wireless Innovations Center (QUWIC), Doha, Qatar*

## **11. References**


22 Will-be-set-by-IN-TECH

After describing the previous contributions in the literature and outlining the differences with the presented approach in Section 2, the problem was defined and formulated in Sections 3 and 4, then the novel proposed method to address the formulated problem was presented in Section 5, and its efficiency was demonstrated in Section 6. Hence, the role of this section is to

In addition to a more thorough and detailed investigation of the topics described in Sections 7 and 8, future work would consist of implementing the proposed methods in a sensor network testbed and of matching the simulation results with actual energy measurements. Another interesting research direction is to consider SNs with variable power sources, and to distinguish between battery powered SNs and SNs having access to renewable energy sources (e.g. solar powered) or mains powered. The problem can be reformulated by imposing a constraint that the latter SNs should be cluster heads since they can transmit large amounts of

Cooperative data transmission in wireless sensor networks was studied with the objective of energy minimization. The problem was formulated into an optimization problem, and efficient suboptimal methods were presented for the two scenarios: the multihop case where the maximum number of hops is allowed and the clustering case where sensors are grouped into cooperating clusters, each headed by a cluster head in charge of the communication with the base station. The two methods were shown to lead to significant energy savings compared to the non cooperative scenario, with the clustering approach leading to better delay results

This work was made possible by an NPRP grant from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility

[1] 3GPP [2006]. 3gpp tr 25.814 3gpp tsg ran physical layer aspects for evolved utra, v7.1.0. [2] Alawieh, B., Zhang, Y., Assi, C. & Mouftah, H. [2009]. Improving spatial reuse in multihop wireless networks-a survey, *IEEE Communications Surveys and Tutorials*

[3] Baek, S. & de Veciana, G. [2007]. Spatial energy balancing through proactive multipath routing in wireless multihop networks, *IEEE/ACM Transactions on Networking*

than the multihop approach. Practical implementation aspects were also discussed.

**9. Future work**

**10. Conclusions**

**Acknowledgment**

of the authors.

**Author details**

**11. References**

11(3): 71–91.

15(1): 93–104.

Elias Yaacoub and Adnan Abu-Dayya

*QU Wireless Innovations Center (QUWIC), Doha, Qatar*

introduce some interesting future research directions.

aggregated data on the LR without suffering from energy shortage.

