# A Stable Backup Routing Protocol for Wireless Ad Hoc Networks
## 4 Conclusions  
In this paper, a novel stable backup routing (SBR) scheme is developed, including procedures of backup route construction and route maintenance. Our backup routes are established by overhearing MAC signals. Due to the fact that the bit error rate of links is considered in building backup routes, the SBR decreases packet loss and improves the delivery ratio significantly. Moreover, in order to repair the broken link reasonably, all backup routes are classified into three categories with different priorities, which are used to ensure stability and shorten end to end delay simultaneously. Without losing generality, SBR can be integrated into the original Ad hoc routing protocols, such as AODV and DYMO. A mass of simulation experiments validate our theoretical analysis and demonstrate that SBR outperforms other comparable schemes.  
Figure 8: Control overhead versus (**a**) pause time and (**b**) CBR data rate.  
Figure 7: Average delay versus (**a**) pause time and (**b**) CBR data rate.  
In the era of 5G Internet of things, although 5G a cellular communication system with centralized architecture can ensure high bandwidth and low delay communication between the 5G terminal and base station, it cannot meet specific requirements of distributed network connection (such as Ad hoc, Wireless Sensor Networks, etc.). In the era of \"ubiquitous networks and Internet of things\", the distributed networks based on its characteristics of no center and rapid deployment will provide a powerful supplement for a 5G cellular system. At the same time, when the base station cannot work normally due to war or natural disasters, the distributed mobile Ad hoc networks can also be used to ensure emergency communication. Therefore, how to optimize the existing wireless distributed network protocol architecture to meet the needs of low latency and high throughput under 5G background is worth further research.  
In the next research work, more actual implementations and experiments will be conducted to obtain more valuable data and we will deeply study the MAC scheduling strategy based on low delay in distributed networks, combine with the routing protocol proposed in this paper, and use a cross-layer mechanism to further reduce transmission delay and improve network throughput.  
Conceptualization, F.Z. and G.Y.; methodology, F.Z.; software, G.Y.; validation, F.Z.; formal analysis, G.Y.; investigation, F.Z.; resources, G.Y.; data curation, G.Y.; writing--original draft preparation, F.Z.; writing--review and editing, G.Y.; visualization, F.Z.; supervision, G.Y.; project administration, F.Z. and G.Y. Author F.Z. and G.Y. contributed equally in this paper. All authors have read and agreed to the published version of the manuscript. This work was jointly supported by the Fundamental Research Funds of Shandong University, No.2019 HW036, the Doctoral Research Funds of Shandong Management University, No. SDMUD201906, the QiHang Research Project Funds of Shandong Management University, No. QH2020Z01 and the Key Laboratory of TCM Data Cloud Service in Universities of Shandong (Shandong Management University).  
The authors declare no conflict of interest.