Comparative Analysis of Hard and Soft Handovers

Introduction

There is a very high demand for high bandwidth mobile data, and this is proving a challenge to the 21st-century telecommunication service providers. The users require a high-velocity entry to web services from their varied topographical areas using their nomadic gadgets. These portability demands prompted the development of new engineering by the Institute of electrical and electronics engineers (IEEE) 802.16e radio engineering which was given the name long-term evolution (LTE). The use of LTE is appropriate for the worldwide interoperability microwave access (WiMAX) facilitating high-speed wireless entrée to web services. The 802.16e supports the handover mechanism due to the introduction of both soft and hard handovers (Lu & Ma, 2011). This article will focus on the hard and soft handover mechanisms highlighting their comparisons.

The Handover Concept

The handover concept entails the transference of an ongoing mobile call or information from one channel to another that is linked to the core network. The primary objective of the handover is to enable mobile subscribers to freely transfer their call from one mobile system to another while maintaining a good radio quality with the base station reducing the interference levels (Yang, Huang & Liu, 2016). In the process, mobile cellular users can receive their calls anywhere in the world at any time by roaming from one cell to another cell providing the needed mobility. The roaming occurs when the link quality of the base station and that of the mobile station of the call on progress declines to a particular threshold level. The initial connection is first broken down and replaced with a handover connection to the cell, target cell. In this case, the network controller determines, depending on the measurement data, the link quality required for the handover process (Becvar & Zelenka, 2006). Prados-Garzon et al. (2016) developed a system level simulator of the virtualized LTE network to describe the workability of the x2-based handover with the ns-3 environment. The implementation of the transfer was achieved, and it was noticed that its preparation takes 6.94ms while its accomplishment duration is 5.31ms which applies to the 5G networks.

Soft Handovers

The soft handovers also known as the “make before break” operate in such a way that the target connection is first linked to the other Node-B and then releases the older link upon establishing the target connection. The mobile gadget and the UTRAN (Universal Terrestrial Radio Access Network) remain connected since the user equipment creates parallel relationships from different Node-B with many sectors meaning the connections are deleted in a way that the links are not interrupted. With the soft handovers, the near-far impact is significantly reduced, the links can tolerate shadowing and communication during roaming is never suspended (Prados-Garzon et al., 2016).

Hard Handovers

On the other hand, with the hard handovers, the connection has to be disconnected first before a new one between the user equipment and the radio network controller is created. Therefore, this type of handover is also referred to as “break before make” for the initial link must be disconnected for the new connection to be established. Such handoffs are instant to reduce the disconnection duration of the call. This type of handover is economical and straightforward since the cellular gadget doesn’t need to make links between two or more channels at ago meaning that only one channel is involved at any interval (Prados-Garzon et al., 2016).

Conclusion

In summary, the handovers are essential in providing roaming services that the contemporary society requires. The applicability of the handover technology has been tested and proved feasible offering a breakthrough in the telecommunication services.

References

Becvar, Z., & Zelenka, J. (2006). Handovers in the mobile WiMAX. Research in Telecommunication technology, 1, 147-150.

Lu, Q., & Ma, M. (2011). Achieving Faster Handovers in Mobile WiMAX Networks. Wireless Personal Communications, 65(1), 165-187. doi:10.1007/s11277-011-0234-6

Prados-Garzon, J., Adamuz-Hinojosa, O., Ameigeiras, P., Ramos-Munoz, J. J., Andres-Maldonado, P., & Lopez-Soler, J. M. (2016). Handover implementation in a 5G SDN-based mobile network architecture. 2016 IEEE 27th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC). doi:10.1109/pimrc.2016.7794936

Yang, X., Huang, X., & Liu, J. K. (2016). Efficient handover authentication with user anonymity and untraceability for Mobile Cloud Computing. Future Generation Computer Systems, 62, 190-195. doi:10.1016/j.future.2015.09.028