eRedCap (3GPP Release 18) is the direct successor to LTE Category 1 and LTE Cat-1bis for mass IoT and M2M connectivity. Both standards deliver approximately 10 Mbps peak downlink and 5 Mbps uplink. Both use a single receive antenna. From an application data rate perspective a device migrating from Cat-1 to eRedCap will notice no difference in normal operation.
The differences that matter sit underneath the headline throughput figure.
Network Generation
LTE Cat-1 operates on 4G LTE networks using the Evolved Packet Core (EPC). eRedCap operates on 5G New Radio with a 5G Standalone core (5GC). This is not just a version number difference – the 5G Core unlocks capabilities unavailable on 4G: network slicing, exposure APIs, and the power saving mechanism (eDRX in RRC_INACTIVE) that eRedCap inherits from the 5G NR IoT stack.
Power Saving
LTE Cat-1 and Cat-1bis have no Power Saving Mode (PSM) and no eDRX in RRC_INACTIVE. eRedCap supports PSM, connected-mode eDRX, and introduces eDRX in the RRC_INACTIVE state – a Release 18 addition not present in RedCap (Release 17). For battery-operated devices reporting infrequently, this is a meaningful operational advantage.
Network Longevity
4G LTE networks will eventually be wound down as operators refarm spectrum. The timeline varies by market but the direction is clear. LTE Cat-1 devices deployed today face an end-of-network horizon. eRedCap devices operate on 5G SA infrastructure with a roadmap through at least 3GPP Release 20 and beyond.
Module Cost
LTE Cat-1bis modules are widely available and inexpensive today. eRedCap modules are expected from 2026 with costs converging toward Cat-1bis pricing as volumes scale through 2027-2028. For devices shipping today, Cat-1bis remains the correct specification. For devices designed to last through the 2030s, eRedCap is the forward specification.