Connected Bus by Wavecom

A SPOF (Single Point of Failure) is any non-redundant component or equipment of a system architecture that, if dysfunctional, would cause the entire system to fail, leading to its downtime. 

In Connected Bus solution architecture, the modular Gateway is sometimes seen as a SPOF. The reliability and resilience of the Connected Bus are critical issues since modular Gateways relies on constant connectivity and data exchange with IoT Manager/Multi-Tenant Platform. 

To minimize the effects of a modular Gateway as a SPOF in a Connected Bus solution, network access and data at all levels are secured. The software is regularly updated and maintained properly for modular Gateways. Additionally, using preventive maintenance, diagnostics, or troubleshooting allows us to detect and solve errors before they affect network functionality of the Connected Bus. A VPN is used to protect network access from unauthorized users or devices. SD-WAN (Software Defined – Wide Area Network) makes a Connected Bus solution more flexible, automatable, resilient, and reliable. This solution is cloud managed by IoT Manager/Multi-Tenant Platform (Figure 1) and supports ZTP (Zero-Touch Provisioning). 

However, the main strategy is focused on using two modular Gateways in a balanced mode, to create redundancy in connectivity, as depicted in Figure 4.

Connected Bus solution is designed for Bus Operators to significantly improve their business efficiency and profitability. 

Through a complete onboard Wi-Fi connectivity solution, Connected Bus provides access to internet and communication to passengers, Real-Time FMS (Fleet Management Service) | Tracking | GPS positioning | CAD – AVL (Computer-Aided Dispatch / Automatic Vehicle Location) and APC (Automatic Passenger Counting). Seamlessly. It also enables integration with CCTV | surveillance video streaming and Ticketing systems through APIs.

The elementary Connected Bus solution’s components comprise a Wavecom Technologies modular Gateway (5G Native) installed in each bus vehicle, which is cloud managed by IoT Manager/Multi-Tenant Platform (5G WAN Manager | SD-WAN) as shown in Figure 2.

• Modular Gateway (5G Native)

Bus onboard equipment refers to single modular Gateway (5G Native) offering the following features:

• 2 x Independent 4G-LTE/5G modules
• 2 x separated dual band Wi-Fi Access Points 
• 1 x integrated GPS
• Possibility of providing information in IoT Manager Platform or via API
• Network resources (OSPF, STP, DHCP Server/Client, NAT, DNS, Link Aggregation, VPN Server/Client, QoS, VLAN …)
• Ethernet and serial interfaces for local connectivity
• VPN over WWAN (4G-LTE/5G) for centralized real-time monitoring and management
• Certified for automotive environment

Modular Gateway has up two 4G-LTE/5G interfaces, which provides redundancy since it uses SIMs from two different Cellular Operators.

• IoT Manager/Multi-Tenant Platform

IoT Manager/Multi-Tenant Platform (5G WAN Manager | SD-WAN | Virtual Networks | Link aggregation | Security) provides a cloud managed ZTP system multi-tenant approach, as it allows a System Integrator to manage multiple modular Gateways. 

IoT Manager /Multi-Tenant Platform (5G WAN Manager | SD-WAN | Virtual Networks | Link aggregation | Security) is able of centralizing all provided functionalities such as:

• Wi-Fi User Access Control
• Network Access Control
• Gateways/Device management
• Real Time equipment’s’ monitoring
• Customizable Captive Portal
• Real Time Fleet Visibility with Route Optimization
• Ability to create CSAT (Customer Satisfaction Surveys)

Minimizing the effects of modular Gateway as a SPOF

A SPOF (Single Point of Failure) is any non-redundant component or equipment of a system architecture that, if dysfunctional, would cause the entire system to fail, leading to its downtime. The SPOFs are undesirable to systems that demand high availability, reliability and resilience, such as on an onboard connectivity architecture. 

In the  Connected Bus Architecture, the modular Gateway is sometimes seen as a SPOF, as shown in Figure 1. In a Connected Bus solution, to ensure reliability and resilience for modular Gateways in order to minimize the effects of SPOF, some procedures are implemented.

• Secure network access and data 

In the Connected Bus solution, a VPN is used to secure network access and data at all levels from unauthorized or malicious users or devices (Figure 3).

SD-WAN virtualizes network functions so that the network can be used over a variety of heterogeneous physical and logical network connections and protocols, such as Wi-Fi and 5G. 

In terms of security issues, tunnel protocols (SD-WAN), security policies and other mechanisms are used to prevent possible attacks to the network, as depicted in Figure 3.

• Architecture with two modular Gateways in a balanced mode

The main strategy is focused on using two modular Gateway in a balanced mode, to create redundancy in connectivity, as depicted in Figure 4. If the modular Gateway is a SPOF, then we can add another one in Bus vehicle. If the first one crashes, the second one will be used. Or we can distribute load across both the modular Gateways.

The architecture presented (Figure 4) involves placing a switch that communicates with 2 modular Gateways, each with two modems. This architecture allows the two modular Gateways to be configured via ZTP and communicate with each other, allowing them to operate in load balanced and/or failover mode.

This is because the two routers constantly exchange messages with each other and if one stops working, the second will take over communications for all internal systems. This means that critical internal services do not suffer from failures in communications with central systems. Thus, we are able to combat the effects of SPOF in a resilient and simple way to implement.

It should be noted that this way is very transparent for internal systems and that it is easily put into service, always maintaining the focus on ensuring flawless communications.

Conclusion

The SPOFs are undesirable to systems that demand high availability, reliability and resilience, such as on an onboard connectivity architecture. 

in order to minimize the effects of SPOF due modular Gateway, Wavecom Technologies provides a cloud managed IoT Manager/Multi-Tenant Platform that improves the reliability and efficiency, when deploying a Connected Bus solution.

In terms of security issues, tunnel protocols (SD-WAN), security policies and other mechanisms are used to prevent possible attacks to the network, minimizing the effect of the modular Gateway as a SPOF.

However the main strategy is focused on using two modular Gateway in a balanced mode, to create redundancy in connectivity. If the modular Gateway is a SPOF, then we can add another one in Bus vehicle. If the first one crashes, the second one will be used. Or we can distribute load across both the modular Gateways.

This architecture allows the two modular Gateways to be configured via ZTP and communicate with each other, allowing them to operate in load balanced and/or failover mode. This way of minimizing the effects of a SPOF, is very transparent for internal systems and it is easy to put into service, always maintaining the focus on ensuring flawless communications.