g., following the HCCA
protocol [12]), each link can provide a guaranteed bandwidth g(li,j) at the application layer.
Following the HCCA specification [12], this bandwidth is linked with the traffic
specification parameters by [14]:
( )
TXOP ,
, 1
phy , overhead SI ,
( )
( )
( ) ( )
i j
i j
i j i j
t l L
g l
L R l T t l ??’
?‹…
=??® ??? ?‹… + ?‹… ??? ??? ??° ??»
(5)
where TXOP , ( ) i j t l is the transmission opportunity duration provided by the HCCA
admission control for the video flow traffic of link li,j, L is the nominal MAC service data
unit (MSDU) size4, SI , ( ) i j t l is the specified duration of the service interval [12] for the
video flow traffic at link li,j, Rphy(li,j) is the physical layer rate and Toverhead represents the
duration of the required overheads corresponding to polling and acknowledgment policies.
As demonstrated by (5), even though the negotiated transmission opportunity duration is
constant per link, the guaranteed bandwidth depends on the provided physical layer rate
Rphy(li,j), which in turn makes it dependent on the chosen modulation5 m(li,j). Finally,
depending on the chosen modulation, Rphy(li,j) may change for each MSDU.
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