One can argue that “pre-4G” networks, basically all those using protocols that do not yet correspond fully with the official International Telecommunications Union definitions, primarily offer the advantage right now of “more bandwidth” and “lower latency.”
Fully-compliant 4G, which will support a minimum of 1 Gbps for stationary deployments and 100 Mbps for mobile deployments, might have some additional features, though.
The next step in the IMT-Advanced (4G) standards process, in addition to the minimum bandwidth capabilities, will be the ability to maintain and hand off sessions that switch between 4G, 3G and Wi-Fi networks, for example.
While 3G refers to a certain amount of data throughput at certain speeds, 4G is additionally about incorporating multiple standards and interoperable technologies. In principle, a user should be able to sustain a video conference call and as they move from a LTE-A network to a HSPA environment to a WiFi environment.
Such sessions should be seamlessly handed off from network to network, with the call (or data session) quality dynamically changing based on the network’s capacity to handle the data traffic involved. Though most of the attention will be paid to the bandwidth thresholds, 4G will also mean interoperable and seamless communications across multiple environments.