5G power-saving cells will keep broadcasting system info on every beam

Samsung, Ericsson, LG and vivo wanted 5G energy-saving cells to send system information only toward the phone that asked for it, cutting radio transmissions to a single beam. Huawei, ZTE, Qualcomm and Xiaomi blocked that, warning it would hurt reception reliability for phones that had moved or hadn't yet requested anything. The legacy rule — broadcast on every beam the cell uses — won, which keeps access reliable but caps how much power a base station actually saves by making system information on-demand in the first place.

The bigger, quieter win was timing. When a phone wakes up a power-saving cell and asks for SIB1 (the block carrying basic cell-access rules), it needs to know when to start listening for the reply. Apple, Samsung, Qualcomm, Huawei and ZTE argued the countdown should start at the end of the Random Access Response window, calling it the simpler, more obvious reference point; Ericsson, Nokia, Lenovo, DOCOMO and Google wanted the earlier starting slot to shave off latency. The end-of-window camp won, meaning phones will wait marginally longer for SIB1 in exchange for a cleaner, less ambiguous specification.

A parallel fight over signaling method went the same direction: MediaTek, Lenovo, ZTE, DOCOMO and Google pushed to fix the SIB1 monitoring offset inside the uplink wake-up signal configuration, in slot units, rather than let the network signal it per-request in the Random Access Response, as Apple, Ericsson, InterDigital and Samsung had wanted. The static approach won, trading away per-phone network flexibility for lower signaling overhead — a pattern that repeated for control-channel parameters (CORESET0, SearchSpaceZero), which Huawei, Qualcomm, Lenovo and 20 other companies agreed will always come from the wake-up signal configuration rather than sometimes from the Master Information Block, closing a case that CMCC, NEC and vivo had wanted to keep for overhead reasons.

Two proposals died outright. A joint request letting a phone fetch SIB1 and other on-demand system information in one message was ruled out of scope for this release, with Google, Samsung, Apple and Xiaomi among 19 companies against it and only Sharp in favor. Separately, a plan by Apple, Samsung, Ericsson and Huawei to repurpose reserved bits in the MIB to help phones locate a neighboring normal cell was dropped after Spreadtrum, vivo, Fujitsu and CATT questioned its benefit; the reserved field stays unused.

Several pieces are still loose, including whether the wake-up signal configuration should grow to carry a shared RA-RNTI (backed by Google and Fujitsu), cell-barring flags (Nokia, Samsung), RedCap parameters (vivo, Tejas) or uplink bandwidth data (Huawei, MediaTek). None of these was decided this quarter, and they will determine how large and capable that configuration message ultimately becomes.