Bluetooth Low Energy is about to get nearly four times faster. The Bluetooth Special Interest Group, which owns the standard, announced on 4 November that it has adopted High Data Throughput (HDT), a feature that raises the top speed of Bluetooth Low Energy from 2 Mbps to 7.5 Mbps.
That is nearly four times faster. HDT is an optional part of the newly adopted Bluetooth Core 7.0, so a phone, watch or pair of earbuds only gets it if its maker builds it in. The first flagship use will be a standardised premium audio mode, expected in 2027, covering lossless and high-resolution sound as well as surround and spatial audio.
The group first previewed HDT in a blog post, which listed five speed steps from 2 up to 7.5 Mbps. Devices can change rate from one packet to the next, so a link that weakens drops to a slower rate instead of cutting out. Its worked example, from early demonstrations by member companies: a few-megabyte transfer that needs around 16 seconds now might need around 4.
Speed is only half the pitch. The group argues HDT can also ease battery drain, since a transfer that ends sooner lets the radio drop back into a low-power state. HDT adds error-correction coding so lost bits can be repaired without resending a whole packet, and it supports longer message integrity checks of 64 and 128 bits, up from 32 bits on current Bluetooth LE.
The technical changes are what make the higher rates workable. HDT adds a new radio mode that packs more bits into each signal using more complex modulation, and it can split a large transfer into smaller blocks, each with its own checksum, so a damaged block is resent alone instead of the whole packet. Packets can carry payloads of roughly 8,000 bytes in the largest mode. A new encryption key schedule lets a connection change keys and integrity-check length when it moves between the old and new radio modes.
The SIG sees uses well beyond headphones: smartwatches and fitness bands syncing sensor data, extended-reality headsets, small AI gadgets that hand work to a phone, and industrial monitoring equipment. Its roadmap also lists lossless audio standardisation, operation in new 5GHz and 6GHz bands and carrying IPv6 over Bluetooth LE, which HDT is meant to complement.
In the announcement, CEO Neville Meijers said HDT brings “a new level of performance” and widens where Bluetooth can be used, from consumer to industrial products. Chip makers lined up behind it too. Nordic Semiconductor’s Øyvind Strøm, for his part, sketched a watch that moves hours of workout data to a phone in seconds and a smart-home device that updates its firmware with almost no wait. Samsung’s Joonsuk Kim, who heads S.LSI CP development, said it gives product makers a stronger foundation.
Nothing changes for gear you already own, since HDT arrives only in products built with it. The release names no devices, and the only date it gives is 2027 for the audio feature.
