Question E2D10:
What does the packet path WIDE3-1 designate?  

Choices:  
A: Three stations are allowed on frequency, one transmitting at a time  
B: Three subcarriers are permitted, subcarrier one is being used  
C: Three digipeater hops are requested with one remaining  
D: Three internet gateway stations may receive one transmission    

Correct Answer is  C: Three digipeater hops are requested with one remaining  

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WIDE3-1 is APRS/AX.25 path notation using the WIDEn-N scheme. The first number is the originally requested number of digipeater hops; the second number is decremented by each hop.

1) Why the correct answer is correct:
- WIDE3-1 means the packet was sent with an original request of 3 hops and currently has 1 hop remaining. It has already been digipeated twice.
- In general, each digipeater that forwards the packet changes WIDE3-1 to WIDE3-0, then removes/consumes it when it hits zero.

2) Why the other choices are incorrect:
- A: “Three stations are allowed on frequency…” — This is unrelated to packet paths; WIDE3-1 is not a channel-access designation.
- B: “Three subcarriers…” — APRS packet paths do not involve subcarriers; they are routing directives for digipeaters.
- D: “Three internet gateway stations…” — I-Gates are not specified by WIDE paths. Internet routing uses paths like TCPIP or q-constructs, not WIDEn-N counts.

3) Useful rules of thumb:
- WIDEn-N notation:
  - $N_{\text{initial}} =$ first number (requested hops)
  - $N_{\text{remaining}} =$ second number (decrements by 1 per digipeater)
  - $N_{\text{used}} = N_{\text{initial}} - N_{\text{remaining}}$
- Example: WIDE3-1 ⇒ $N_{\text{initial}}=3$, $N_{\text{remaining}}=1$, so $N_{\text{used}}=2$.
- Common recommended paths (local practice varies): WIDE1-1, WIDE2-1, or WIDE2-2 for mobile/terrestrial APRS. Avoid excessive hops to reduce network congestion.

This is why the correct choice is: Three digipeater hops are requested with one remaining.