In my experience, Gig MAN/WAN does not use POS.
I have worked with 3 MAN solutions, and all used 8B10 signaling, Ethernet framing and operates at true gig speeds.
"ZX" GBIC have a 70 KM range over single mode fiber.
JDS Uniphase has a 100 Mile (140 KM) over single mode fiber.
The Nortel DWDM solution places the Gig on a lambda, but its otherwise gigabit Ethernet. Distances are 40 KM +. The advantages of DWDM is the ability to transport multiple GIG over the same single mode fiber.
I am sure that there are other comparable solutions that I am unaware of.
Regards;
Doug