Algorithm for Vertical Handover Decision in Vehicular Environment

Introduction

With the mobile becoming an “All in one device”, subscribers expect multiple applications to run concurrently without any break, while on the move across the globe. Vertical handover provides seamless connectivity to the mobile users, as they move in and out of the networks, operating on different access technologies. An efficient Vertical Handover Decision Algorithm (VHDA) can ensure that the user is connected to best network at all the times (Yan, Sekercioglu, & Narayanan, August 2010).

Improvement in the Quality of Experience (QoE) and meeting the demands of the mobile users can be achieved through smart Vertical Handover (VHO) which provides the best Quality of Service (QoS) (Marquez Barja, et al., December 2014). Handover should have low latency, jitter and the minimum packet loss (Marquez Barja, Calafate, Cano, & Manzoni, An overview of vertical handover techniques: Algorithms, protocols and tools, 2011) (M, Liao, & Xie, 2013).

The process of handover can be divided into four steps:

• 1.

  Handover information gathering;

• 2.

  Decision of Handover;

• 3.

  Transfer of the radio link;

• 4.

  Assignment of channels (Yan, Sekercioglu, & Narayanan, August 2010).

The Handover information gathering phase is responsible for capturing the necessary information pertaining to the network capabilities and user preferences. This phase is also referred as System discovery phase (Marquez Barja, Calafate, Cano, & Manzoni, A geolocation-based Vertical Handover Decision Algorithm for Vehicular Networks, Oct 2012) (Barja & Calafate, Evaluation of a technology-aware vertical handover algorithm based on the IEEE 802.21 standard, 2011).

The Handover decision making is done based on the information gathered about all the available networks and the best candidate network is selected for handover (M, Liao, & Xie, 2013) (Barja J. M., Calafate, Cano, & Manzoni, August 2011) (Barja J. M., Calafate, Cano, & Manzoni, 2012).

Mathematical modelling and Fuzzy Logic have been employed to develop VHDAs.

System Model

The proposed system model captures the following six important parameters as inputs to the handover algorithm:

• 1.

  RSS (in dbm)

• 2.

  Channel Capacity (in Mbps)

• 3.

  Quality of Service (QoS)

• 4.

  Cost (in INR)

• 5.

  Battery Life (in Hrs)

• 6.

  Velocity of the user (in m/secs)

Quality of Service is decided by network parameters like Latency, Jitter and Packet Loss.