diff --git a/obu-cam-transmistter/main/geonet.c b/obu-cam-transmistter/main/geonet.c
index 60ea6e0..418c92c 100644
--- a/obu-cam-transmistter/main/geonet.c
+++ b/obu-cam-transmistter/main/geonet.c
@@ -19,7 +19,10 @@ int geonet_wrap_shb(const uint8_t *its_payload, int its_len,
     // ---- GN Basic Header (4 bytes) ---- (EN 302 636-4-1 clause 9.6)
     *p++ = (uint8_t)((1 << 4) | 1); // version=1, NextHeader=1 (Common Header, unsecured)
     *p++ = 0x00;                    // reserved
-    *p++ = 0x83;                    // lifetime (~60s in the base/multiplier encoding) - tune if needed
+    // Lifetime: multiplier in the upper 6 bits, base in the lower 2 (0 = 50 ms, 1 = 1 s, 2 = 10 s,
+    // 3 = 100 s). 0x05 = 1 x 1 s, what real stations send their CAMs with. Was 0x83, commented as
+    // ~60 s but decoding to 32 x 100 s = 3200 s. See obu-firmware's geonet.c.
+    *p++ = 0x05;
     *p++ = 1;                       // remaining hop limit = 1 (SHB single-hop; matches CAM in the Rust reference)
 
     // ---- GN Common Header (8 bytes) ---- (clause 9.7)
diff --git a/obu-firmware/main/geonet.c b/obu-firmware/main/geonet.c
index e80ec36..477a127 100644
--- a/obu-firmware/main/geonet.c
+++ b/obu-firmware/main/geonet.c
@@ -33,7 +33,12 @@ int geonet_wrap_shb(const uint8_t *its_payload, int its_len,
     // ---- GN Basic Header (4 bytes) ---- (EN 302 636-4-1 clause 9.6)
     *p++ = (uint8_t)((1 << 4) | 1); // version=1, NextHeader=1 (Common Header, unsecured)
     *p++ = 0x00;                    // reserved
-    *p++ = 0x83;                    // lifetime (~60s in the base/multiplier encoding) - tune if needed
+    // Lifetime: multiplier in the upper 6 bits, base in the lower 2 (0 = 50 ms, 1 = 1 s, 2 = 10 s,
+    // 3 = 100 s). 0x05 = 1 x 1 s, which is what every other station in
+    // its-g5-receiver-firmware/recordings sends its CAMs with. This was 0x83, commented as ~60 s but
+    // decoding to 32 x 100 s = 3200 s, beyond the 600 s itsGnMaxPacketLifetime a sender may use at
+    // all. A DENM would want a longer one (the captured GeoBroadcast DENMs use 0x79, 30 s).
+    *p++ = 0x05;
     *p++ = 1;                       // remaining hop limit = 1 (SHB single-hop; matches CAM in the Rust reference)
 
     // ---- GN Common Header (8 bytes) ---- (clause 9.7)