Three methods of data transfer from the server to the client. They're all correct. They're all used in asset tracking systems, though for totally different purposes. Ever wonder which one to choose and why? Here's that article.
The common problem that all of them solve
All patterns of data transmission try to solve one single problem: how does the client know when there's been an update? They're just solving the same problem using different methodologies depending on how frequently updates occur and how quickly they need to be received.
Polling
Client asks server continuously: "anything new?"
Pull Model
Client polls server at a set interval of every 5 seconds, every 30 seconds, or every minute. Server responds with latest information regardless of any change. Easy, dependable, and works anywhere. Inefficient – server wastes processing power returning empty replies because you paid for the call no matter what.
Comparison: Checking your email for new messages by refreshing your inbox every 30 seconds. Effective but inefficient as you waste effort refreshing even when there are no emails to check.
✓ Ideal for situations where
- Updates rarely occur (a few times a minute)
- Minimal network requirements
- Operating behind restrictive firewalls
✗ Difficulties arise when
- Frequent data updates occur
- Latency is critical
- Large scale (10,000 clients polling creates server headaches)
📍 For asset tracking
Not appropriate for live updates — retrieving daily usage reports, pulling maintenance schedules, verifying fleet status from a management dashboard that updates every couple of minutes. Not good for anything that needs to be urgent.
Webhooks
Your server gets called when an event happens
Push-based
You give the server an endpoint URL. The server will send an HTTP POST to your URL whenever the relevant event happens. You don't poll — you just wait for your server to get the event message. Efficient, since it only sends HTTP messages when something interesting has occurred. Requires that your receiving end is publicly reachable and capable of handling HTTP messages.
Comparison: setting up email notifications rather than constantly refreshing your email inbox. No action on your part until you have something to act upon.
✓ Ideal for situations where
- Event happens once in a while
- When communicating with other services
- Event triggers some workflow
✗ Difficulties arise when
- Lots of events firing per second
- Receiving end does not accept HTTP messages
- Two-way communication is required
📍 For asset tracking
Ideal for zone exit alerts, maintenance reminders, threshold violations, and ERP integrations. If a truck leaves a defined area or if a sensor crosses a critical threshold — trigger a webhook to Slack, an ERP, or a paging service. Once-off event, once-off POST action, problem solved.
WebSockets
Continuous two-way communication through an open connection
Two-Way
One persistent TCP connection established between client and server which allows both ends to communicate without requesting another connection. The fastest and most efficient way of communicating — ideal for streaming data. Requires more coding than polling or webhooks but is unparalleled for dashboard purposes.
Comparison: Imagine a phone conversation rather than text messaging where the connection remains open allowing both participants to communicate anytime with no need to establish a new connection each time.
✓ Ideal for situations where
When data updates constantly
Need for less than second latency
Client-side sends data as well
✗ Difficulties arise when
When corporate firewalls block connections that aren’t HTTP
When stateful load balancers aren't available
When updates are rare and connection overhead becomes pointless
📍 For asset tracking
A crucial component of live dashboards – live map with dynamic vehicle pin markers, live sensor data, and live alert feeds. All updates from the IoT devices get passed through WebSockets to live dashboards in just milliseconds.
Comparison
| Criterion | Polling | Webhooks | WebSockets |
|---|---|---|---|
| Direction | Client → Server | Server → Client | Both-way communication |
| Speed (latency) | Poll interval in seconds | Real-time (event-triggered) | response time sub-seconds |
| Effectiveness | Low (empty results) | win – only triggered by events | High (always connected) |
| Ease of use | simple | somewhat complex | balanced (more complex) |
| Firewall friendliness | passes firewall | passes firewall | sometimes firewalled |
| Ideal for asset tracking | reports | notifications | live dashboards |
The interplay of the three together in one system
The best asset tracking solutions don’t choose – they implement all three for distinct purposes:
A full asset tracking communication pipeline
Polling – dashboard polls for summary information about fleet every 5 minutes. Live updates are not required, just a snapshot.
Webhooks – violation of geofence triggers a POST to Slack, ERP, and another custom URL simultaneously. Event-driven, loosely coupled, instant.
Websockets – live ops dashboard displays continuous real-time asset locations, sensor data, and alerts to authenticated users.
Hybrid tip – if you can't use Websockets because of corporate proxy, Server-Sent Events (SSE) is a great alternative to Websockets when it comes to the live dashboard – HTTP, built-in reconnection logic, uni-directional server -> client message protocol, covers almost all use cases of dashboards.
AssetTrackPro utilizes all three approaches in production – Websockets are used for live dashboard functionality, webhooks for integrating alerts into ERP and Slack, and REST APIs for reporting/historical data access. Learn more →
Planning to develop a real-time asset tracking solution? AssetTrackPro’s platform provides WebSocket streaming capabilities, webhook delivery, and APIs for your reports – everything is ready to use out-of-the-box.
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