At Real Wireless we often find ourselves needing to explain complex wireless concepts to non-specialists. Analogies often help.
In the world of LTE we have found two analogies especially helpful:
- OFDMA is like a grand piano: The keys are individual OFDM subcarriers (“tones”). A specific allocation of users to tones (and hence resource blocks) is like playing a chord (albeit one which usually requires more than ten fingers!). One beat in the bar represents a 1ms scheduling interval.
- Resource scheduling is like playing TETRIS: The resource allocation algorithm in the scheduler, which is such a great source of flexibility and differentiation amongst vendors, is like the player in a game of TETRIS. The playing pieces are the individual elements of data from/to users which require scheduling. The TETRIS columns correspond to the resource blocks in frequency terms, and the rows are the 1ms scheduling intervals in time. The more skilled the player, the better the scheduler is able to combine the needs of different users within the resources available.
And combining the two, a musically gifted player can select notes and rhythms / rows and columns / times and frequencies which are musically harmonious / make best use of the frequency and time-selective radio channel. But maybe that’s taking the analogy too far!
We’ve used these analogies to good effect several times, including at the courses we run in association with Intellect and the University of Surrey. We’d be interested in hearing whether these appeal to you and if you can suggest better ones.