Timeslotting

Timeslotting is a method for organizing the use of a shared resource by dividing time into discrete, fixed-length intervals called timeslots. Each timeslot is assigned to a specific signal, user, or task, allowing multiple streams to occupy the same channel or processor in a sequential, non-overlapping fashion. Timeslotting is a central concept in time-division multiplexing and in various scheduling algorithms used by operating systems.

In telecommunications, time-division multiplexing splits a communications channel into a frame consisting of several timeslots. Each timeslot carries data from a particular source, enabling multiple channels to share a single link with predictable timing. Systems require accurate clock synchronization to align slots. A well-known example is GSM, which uses frames containing eight timeslots per channel.

In computer systems, timeslotting appears as time slicing in multitasking operating systems. A scheduler assigns a fixed time quantum to each runnable process; when the quantum expires, the processor switches to another process. This approach supports responsiveness and fairness but incurs context-switch overhead and can suffer from latency for long-running tasks or real-time workloads.

Timeslotting relies on clock distribution and low jitter; misalignment can cause data loss or inefficient utilization. Variants include fixed-length slots with static allocation or dynamic slot assignment based on demand and quality-of-service requirements. Fixed slots simplify implementation but can waste capacity; dynamic schemes improve efficiency at the cost of complexity and potential scheduling delays.

Timeslotting has applications in telecommunications, computer scheduling, and digital networks, with historical roots in early telephone networks and evolving towards flexible multiplexing in modern broadband and wireless systems.