BLE 5.0 vs BLE 4.2 in Smart Locks: Range, Speed and Power Explained

Every Philips and Auslock smart lock sold in Australia uses Bluetooth Low Energy (BLE) for phone-to-lock communication. But the BLE version — 4.2 vs 5.0 vs 5.1 vs 5.2 — has significant practical implications for range, unlock latency, battery life and security. This article breaks down what each version adds and why BLE 5.0 (via the Nordic nRF52840 SoC) is the minimum standard for smart locks installed in 2024.

BLE Version Timeline and Key Features

Version	Year	Max Speed	Max Range	Key Feature
BLE 4.0	2010	1 Mbps	~30m	Original LE spec
BLE 4.1	2013	1 Mbps	~30m	Topology improvements
BLE 4.2	2014	1 Mbps	~30m	LE Secure Connections, DLE (247-byte MTU)
BLE 5.0	2016	2 Mbps (HS mode)	120m (LE) / 400m+ (Coded PHY)	Coded PHY, 2x speed, 4x range
BLE 5.1	2019	2 Mbps	400m+	Direction Finding (AoA/AoD), LE Audio groundwork
BLE 5.2	2020	2 Mbps	400m+	LE Audio, Enhanced ATT, LLCP improvements

BLE 5.0 Coded PHY: Long Range Mode

The most impactful BLE 5.0 feature for smart locks is Coded PHY — a Forward Error Correction (FEC) mode that trades throughput for range and reliability through walls and concrete floors. Two coding schemes are available:

• S=2 (125 kbps effective): 2x range improvement over 1M PHY, moderate power increase
• S=8 (500 kbps effective): 4x range improvement, higher power but still suitable for battery locks in advertising mode

For smart lock installations in apartment buildings, Coded PHY means the lock can maintain BLE connectivity through two concrete walls — critical for lobby installations where residents approach from a corridor. The nRF52840 switches PHY automatically based on RSSI; when the phone is close (>-70 dBm), it uses 2M PHY for fastest unlock. When the phone is further away (corridor approach), it drops to Coded PHY S=2 to maintain the connection.

2 Mbps High-Speed Mode

BLE 5.0's 2 Mbps LE mode doubles throughput from the original 1 Mbps (after protocol overhead, effective application throughput is approximately 1.4 Mbps vs 0.7 Mbps). For smart locks, this primarily matters for:

• OTA firmware updates: A 240 KB firmware image transfers in ~1.4 seconds vs ~2.8 seconds on 1M PHY
• Access log synchronisation: Downloading 500 access log entries transfers in ~0.4 seconds vs ~0.8 seconds
• Biometric template backup: Exporting 100 fingerprint templates (400 KB total) takes ~2.3 seconds vs ~4.6 seconds

The unlock command itself (typically 20 bytes) transfers identically fast on 1M and 2M PHY — the latency difference for unlock is not in throughput but in connection establishment time.

Advertising Interval and Unlock Latency

The connection setup time dominates unlock latency. When a phone approaches, it must: (1) discover the lock's BLE advertisement, (2) initiate connection, (3) complete encryption setup, (4) authenticate and send the unlock command. The advertising interval determines step 1:

Advertising Interval	Avg Discovery Time	Battery Impact	Used When
20 ms	~10 ms	High (continuous TX)	Not typical for locks
100 ms	~50 ms	Moderate	Active unlock mode
200 ms (default)	~100 ms	Low	Normal lock standby
1000 ms	~500 ms	Very low	Deep power-save mode

Philips DDL locks default to 200 ms advertising interval for a balance of responsiveness and battery life. In BLE 5.0 with 2M PHY, total time from phone-in-range to unlock is typically 350–600 ms. On BLE 4.2 locks with 100 ms advertising interval, the same sequence takes 450–800 ms — noticeable but not dramatic for residential use.

Connection Interval: The Unlock Command Timing

Once connected, BLE devices exchange data at the connection interval. Smart locks use 30–100 ms connection intervals for unlock commands. At 30 ms, the unlock command (sent as a GATT Write) reaches the lock within one connection interval of being issued — delivering sub-100 ms response from app tap to motor movement. At 100 ms intervals, the worst case is ~100 ms command latency — imperceptible to users.

LE Privacy: Resolvable Private Addresses

BLE 5.0 formalised LE Privacy using Resolvable Private Addresses (RPA). Instead of broadcasting a fixed Bluetooth MAC address (which would allow tracking a lock's location over time by passive scanners), the lock generates a new RPA every 15 minutes using the Identity Resolving Key (IRK) shared with paired phones. An observer with a BLE sniffer sees a different "device" every 15 minutes, preventing long-term tracking of the lock installation. Only paired phones (holding the IRK) can resolve and recognise the lock.

Early BLE 4.0/4.1 locks without RPA broadcast their permanent MAC address — a privacy concern flagged by the Australian Privacy Act's provisions on location tracking of individuals in residential premises.

Practical Comparison: Philips 7300-5HWS vs Older BLE 4.2 Models

The Philips 7300-5HWS (2026 model, nRF52840, BLE 5.0) compared to older BLE 4.2 budget locks:

Feature	Philips 7300-5HWS (BLE 5.0)	Typical BLE 4.2 Lock
Unlock latency	350–500 ms	500–900 ms
Wall penetration	Coded PHY: 2 concrete walls	1 concrete wall
OTA update time (240KB)	~1.4 s	~2.8 s
MAC address privacy	RPA (rotates every 15 min)	Static MAC (trackable)
Encryption	LE Secure Connections (P-256 ECDH)	Legacy pairing (PIN)
MTU	247 bytes	23 bytes (default)

Auslock G3 Gateway: BLE 5.0 Central Mode

The Auslock G3 gateway adds a Nordic nRF52840 module specifically for BLE 5.0 Central mode operation. In Central mode, the gateway acts as a BLE master — actively scanning for and connecting to nearby Auslock locks to check status, push firmware updates or relay remote unlock commands from the cloud when the lock is out of the user's phone range. This is particularly useful for rental property managers who need remote lock control without being physically present.

Conclusion

BLE 5.0 is not merely a marketing increment — Coded PHY long-range mode, 2 Mbps high-speed transfers, LE Privacy with rotating addresses and LE Secure Connections with ECDH P-256 collectively deliver a meaningfully better smart lock experience. For any new installation in Australia, specify BLE 5.0 locks: Philips DDL series and all Auslock H/S/T models meet this standard.