Understanding SMS Latency and Queuing

Delivering SMS at scale is a top-of-mind consideration when planning for high-traffic events, such as Ramadan Sale or Black Friday / Cyber Monday. Understanding how your SMS provider prepares messages for delivery and what are the associated latency costs is crucial for the efficient planning of campaigns or mass notifications.

Latency
There are two factors that contribute to SMS delivery latency via any SMS provider:

• Platform processing latency

• Mobile operator latency

• Platform processing latency is the time it takes for Unifonic or any other SMS provider to accept a customer's API request, perform phone number validation, and confirm the legitimacy of the request.

• Mobile operator latency is the time it takes for the mobile service provider to send the message to the mobile device.

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Queuing contributes the most to platform processing latency because mobile operator connections are shared among all Unifonic customers.

Queuing
There are limits to how fast SMS can be sent on mobile networks. When Unifonic receives SMS requests from customers, these requests are queued in the order in which they are received. The queue is shared by all Unifonic customers, so the waiting time depends on the size of the campaign and the number of messages we received from other customers before the campaign started.
We will soon provide detailed documentation on how to calculate your campaign wait time.