Link Bonding: Enhancing Connectivity and Resilience for Emergency Services

Link bonding, also known as link aggregation or WAN bonding, is a technology that combines multiple internet connections into a single, unified connection to increase bandwidth, improve application resiliency, and enhance overall network performance. This approach is especially beneficial for organisations requiring reliable and high-performance connectivity, such as emergency services.

Link bonding intelligently aggregates multiple wired or wireless links — such as LTE, 5G, broadband, Wi-Fi, and Satellite — into one logical connection. This aggregation allows data packets to be distributed across the combined links, effectively increasing throughput and providing redundancy. If one link experiences issues or goes down, the traffic automatically reroutes over the remaining active connections, ensuring continuous network availability.

Link bonding is especially useful for emergency services that may need to operate in areas with limited or unreliable connectivity options, making it particularly beneficial for emergency services field operations. Let’s take a look at what Link bonding enables in more detail:

1. Enhanced Reliability and Resiliency: Emergency services require uninterrupted connectivity to coordinate responses and access critical information. Link bonding minimises downtime by providing seamless failover between multiple connections. If one link degrades or fails (e.g., a cellular tower goes down), traffic automatically shifts to other available links without dropping sessions or losing data. This seamless continuity is crucial during disasters when infrastructure may be compromised.

2. Increased Bandwidth: Combining multiple links boosts available bandwidth, enabling faster data transfer, improved video streaming, and better support for mission-critical applications like real-time video feeds and communication platforms.

3. Improved Application Performance: Intelligent bonding optimises traffic distribution based on application priority, ensuring that essential services receive the bandwidth they need without interruption. Load balancing in link bonding enables traffic to be distributed intelligently across all active links based on current performance and priority. Critical voice and alert messages get the highest priority, while less urgent data — like administrative uploads — uses remaining capacity.

4. Simplified Network Management: Modern link bonding solutions often include cloud-based management, providing centralised control and monitoring of all connections, which is crucial during emergency response scenarios. A single dashboard provides real-time visibility into link health, throughput and latency. Operations teams can set policies, adjust priorities and troubleshoot issues from a unified console.

5. Cost Efficiency: By leveraging a mix of connection types, including cost-effective wireless options, organisations can reduce reliance on expensive dedicated lines or singular satellite connections while maintaining high availability. By pooling available bandwidth from various networks, link bonding can achieve data rates far exceeding what any single link can provide. This is vital for transmitting high-definition video from incident scenes, real-time telemetry from drones or remote sensors, and large data files between command centres.

Ericsson Intelligent Link Bonding handles failover through intelligent traffic management that continuously monitors the health and status of each connection in the bonded link. If one connection fails or becomes unreliable, the bonding technology dynamically redirects all traffic away from the failed link to the remaining active links, ensuring uninterrupted connectivity. This failover process is seamless and automatic, providing organisations with high availability and resilience.

Ericsson offers Cradlepoint routers designed specifically for link bonding with multi-WAN capabilities and advanced software that manages link bonding in one of three ways:

1. Flow duplication for high resiliency

In this mode, identical packets are sent over two links at the same time. Even if a packet is lost on one link due to a temporary signal drop, the packet on the other link gets through, ensuring the application remains connected. This is especially useful for critical and latency-sensitive applications like VoIP (Voice Over IP), where even momentary drops can degrade communication. While this may not seem bandwidth-efficient, it offers near-100% reliability for sensitive applications by eliminating the risk of packet loss due to network instability.

2. Flow balancing for cost savings

Flow balancing, on the other hand, is about distributing traffic flows across multiple links based on predefined weights or percentages. For instance, a branch office with both wired broadband and a cellular link might send 60% of traffic over the wired link and 40% over cellular. This optimises cost and performance, reserving the faster or cheaper link for the bulk of activity while ensuring redundancy. In mobile scenarios, the same principle applies — balancing between cellular providers or between cellular and satellite, based on defined policies.

3. Bandwidth aggregation for high bandwidth

Bandwidth aggregation is the mode most commonly associated with link bonding. It involves combining two or more WAN connections to increase the overall bandwidth available for large data transfers. In practice, this doesn’t always result in a simple doubling of speed due to network overhead and router throughput limits, but it can significantly boost performance for large file uploads or real-time video uploads. For example, an emergency services vehicle can leverage bandwidth aggregation to upload large video files from a natural disaster site. With aggregated links, the vehicle can use multiple cellular connections to transmit footage back to the command centre faster and more reliably.

Emergency services can equip vehicles and command centres with these multi-WAN bonding routers, combining LTE/5G cellular connections with satellite or wired broadband where available. This setup ensures continuous connectivity even if one or more links fail or become congested.

Link bonding empowers emergency services organisations with robust, high-performance, and resilient networking capabilities that are critical during emergencies. By intelligently combining multiple connections, these organisations can ensure continuous communication, faster data access, and better overall operational efficiency.

Image credit: iStock.com/Julia Gomina