Table 1 Differences between cross-device FL and cross-silo FL

Setting

Clients are usually large institutions. Each client reserves a large number of training samples and has sufficient training resources.

Clients are usually portable devices and lack training resources.

Data availability

Clients are almost always available

Only some clients can be used for training at certain time periods.

Federation scale

The number of clients is usually less than 100.

The amount of the client is about \(10^{10}\).

Primary bottleneck

Communication and computation

Communication

Addressability

Each client is assigned an identity.

Customers usually cannot be directly indexed.

Client reliability

Usually few errors.

High error rate.

Data partition axis

Horizontal or vertical.

Horizontal.