Since the State Police operate on a trunked system, there is no association between roadways and "frequencies." Taking your question to refer to "talkgroups:"
Route 93:
NH border to Sullivan Square: A PTL 1 (A-1)
Sullivan Square to Kneeland Street: H PTL 1 (H-4)
Kneeland Street to Route 24: H PTL 2 (H-6/H-7)
Route 24 to Route 95: A PTL 2 (H-2)
Routes 95 and 495 cross too many station boundaries to list.
Route 128 is wholly included in Route 95, except for the portion between Route 24 and Route 3 (Braintree split).
Sullivan Square (roughly) through the O'Neil Tunnel and down to Columbia Road (roughly) is Troop E, not H. That was all moved around 2002 by the legislature when that part of the road was moved to the Turnpike for financial reasons. It can get confusing at times because some of what seems to be the same road is covered by Troop H, some by Troop E, the Sumner and Callahan Tunnels are on Troop F, and north of the Zakim Bridge is Troop A.
Now that the Turnpike has been turned over to the MA DOT, this could all change again.
H6 (H PTL 1) covers I-93 down to Braintree. H7 (H PTL 2)then covers I-93 to I-95 and down Route 24 to the Brockton line. Being the state police, if it's busy patrols can be sent into other Barracks (I guess they call them stations now) areas to help out.
Bumpbailey has asked this same question over at Scannewengland.net, where he received the same set of answers. Maybe now he'll believe us.