**5. Conclusions**

This chapter presents a concept of fog enabled cellular networks (FeCN), where computing, storage, and network functions are provisioned closer to end users in order to improve the service QoS. In addition, to guarantee service continuity and QoS, service migration is introduced to ensure that services always follow the end users through migration from the current fog server to the target one. A QoS-aware service migration strategy based on the existing handover procedures is firstly proposed to balance the benefits and costs of migration. A case study using a realistic vehicle mobility pattern for Luxembourg scenario is carried out through simulation to evaluate the performance of the proposed schemes. Results show that low end-to-end latency (e.g., 10 ms) for vehicular communication can be achieved, while the total number of migrations for each user in the whole journey can be decreased significantly.

To deal with the situation that the target fog node does not have enough resources to support the migrated services, a distributed fog computing resource management scheme is introduced. The scheme purposely selects low-priority (LP) services and migrates those services to carefully selected neighboring fog nodes so that QoS for high-priority (HP) migration services can be served at the target fog node. LP service selection algorithm is proposed to minimize the migration costs for those services, and neighboring fog node selection algorithm is proposed for selecting a fog node that provides enough resources for LP services with also satisfied QoS. Simulation results show that the one-hop access probability for HP services increases significantly, while the service unavailability for LP services can also be well reduced.

During service migration, both the traffic generated by migration and other traffic (e.g., control information, video) are transmitted via mobile backhaul networks. To balance the performance of the two kinds of traffic, we propose a delayaware bandwidth slicing mechanism in PON-based mobile backhaul networks. The method tries to guarantee the transmission of migration traffic within the deadline, while at the same time minimizing the negative impact on non-migration traffic. Simulation results show that migration data can be transmitted successfully in a required time threshold, while the requirements of latency and jitter for non-migration traffic with different priorities can be well satisfied.

**Author details**

, Xiaoman Shen2

2 Zhejiang University, Hangzhou, China

provided the original work is properly cited.

, Lei Chen3

1 Chalmers University of Technology, Göteborg, Sweden

3 RISE Research Institutes of Sweden, Göteborg, Sweden

\*Address all correspondence to: lei.chen@rise.se and jiajiac@chalmers.se

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\* and Jiajia Chen<sup>1</sup>

*Low-Latency Strategies for Service Migration in Fog Computing Enabled Cellular Networks*

*DOI: http://dx.doi.org/10.5772/intechopen.91439*

\*

Jun Li<sup>1</sup>

**45**
