What’s Up With the EBR Element?
Alright, here’s the deal. The Expedited Bandwidth Request (EBR) element ain’t in every frame – it’s an optional part of the 802.11 spec, but when it shows up, it means business. This thing is all about telling the AP, “Yo, I got traffic and it’s hot – make room!”
Why EBR Even Exists
The EBR is basically a tiny flag inside a frame that says: “Hey AP, this TSPEC request I’m sending? It’s kind of a big deal.” You’ll mostly find it mentioned in the deep corners of the spec – stuff like interworking with external networks and even emergency call support. So yeah, we’re not talking about your average cat video stream here.
When and Where It Shows Up
- Sender → Receiver? Comes from a non-AP STA and hits the AP. It’s the STA that says, “I need that QoS hookup.”
- Frame Type? Sits inside an ADDTS Request frame. If the STA’s trying to lock in a Traffic Stream (TS), this is where EBR gets its ride.
- Optional? Yep – but only if
dot11EBRActivated = trueon that STA. If not, forget it. No EBR allowed. - Needs TSPEC? 100%. You can’t send an EBR without a TSPEC. They’re a package deal.
- One Per Frame? Always. No double-dipping. Just one EBR per ADDTS.
What’s Inside This Thing?
EBR uses the classic 802.11 IE format. You’ve seen it before: Element ID, Length, then the actual content – which in this case is just one field:
- Precedence Level – That’s the key. A single byte that tells the AP how urgent this traffic is. Higher value? More urgent. Plain and simple.
No fuss. No drama. Just a straight-up “hey I need this stream handled like, now.” The AP reads that level and decides whether to grant you your golden slice of airtime.
Real Talk: When Would You Actually Use This?
Imagine your STA is about to make a voice call, or start an emergency alarm flow, or do anything time-critical. That’s when you might toss in the EBR. It’s like waving a little priority flag at the AP and saying, “Don’t throw me in the best-effort queue, bro.”
So yeah – not for every TS. But when it counts, the EBR’s the guy you want backing you up.