EP1089500A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Fair packet scheduler and scheduling method for packet data radio
Assignee: Nortel Networks Ltd
•
Filing: 2000-07-14
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Granted: —
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Expires: 2020-07-14
Abstract
Abstract A method of selecting which one of a number of wireless station is to be allocated a particular transmit opportunity is provided, for example the opportunity to transmit an air interface unit such as a MAC frame. For each wireless station, a transaction length is maintained indicating how many transmit opportunities are required to transmit an upper layer packet to or from the wireless station, and a delay parameter is also maintained for each wireless station indicative of how long since the wireless station was last selected. A group of wireless stations to compete for the right to transmit or receive during the particular transmit opportunity is selected, and for each of the group of the wireless stations, a transmit priority is computed which is a function of transaction length and the delay parameter. Finally, the wireless station in the group of wireless stations with the highest transmit priority is selected as the wireless station to transmit or receive an air interface unit during the particular transmit opportunity. Preferably, the transmit priority is also a function of a wireless station priority for each wireless station.
Inventors
- 👤 Ghassan Naim
- 👤 Akbar Rahman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 07:03
CPC Classifications
H; H04; H04L; H04L47/00; H04L47/10; H04L47/24; H04L47/2425; H04L47/2433; H04W; H04W72/00; H04W72/50; H04W72/56; H04W72/566; H04W8/00; H04W8/02; H04W8/04
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
121 words
A method of selecting one of a plurality of wireless
stations to be allocated a particular transmit opportunity
comprising: maintaining a respective transaction length for each
wireless station and maintaining a respective delay parameter
for each wireless station indicative of how long since the
wireless station was last allocated a transmit opportunity; selecting a group of said wireless stations to
compete for the transmit opportunity; for each of the group of said wireless stations,
computing a respective transmit priority which is a function
of the respective transaction length and the respective delay
parameter; and selecting a wireless station in said group of said
wireless stations with the highest transmit priority as the
wireless station to be allocated the particular transmit
opportunity.
Claim 2
Dependent Claim
15 words
A method according to claim 1 wherein said transmit
opportunities are forward link transmit opportunities.
Claim 3
Dependent Claim
15 words
A method according to claim 1 wherein said transmit
opportunities are reverse link transmit opportunities.
Claim 4
Dependent Claim
28 words
A method according to claim 1 wherein the
transaction length indicates how many transmit opportunities
are required to transmit a respective upper layer packet for
the wireless station.
Claim 5
Dependent Claim
23 words
A method according to claim 1 wherein said transmit
priority is also a function of a wireless station priority for
each wireless station.
Claim 6
Dependent Claim
47 words
A method according to claim 1 further comprising: maintaining a respective measure of how long until
each particular wireless station was last allocated a transmit
opportunity; wherein said transmit priority is also a function of
how long until a timeout will occur for the respective
wireless station.
Claim 7
Dependent Claim
47 words
A method according to claim 5 further comprising: maintaining a respective measure of how long until
each particular wireless station was last allocated a transmit
opportunity; wherein said transmit priority is also a function of
how long until a timeout will occur for the respective
wireless station.
Claim 8
Dependent Claim
23 words
A method according to claim 1 wherein said transmit
priority is an increasing function of delay and a decreasing
function of transaction length.
Claim 9
Dependent Claim
30 words
A method according to claim 5 wherein said transmit
priority is an increasing function of delay, a decreasing
function of transaction length, and an increasing function of
wireless station priority.
Claim 10
Dependent Claim
46 words
A method according to claim 6 wherein said transmit
priority is an increasing function of delay, a decreasing
function of transaction length, an increasing function of
wireless station priority, and a decreasing function of how
long until a timeout will occur for the respective wireless
station.
Claim 11
Dependent Claim
28 words
A method according to claim 1 wherein when multiple
wireless stations in the group have the highest transmit
priority, one of the multiple wireless stations is selected
randomly.
Claim 12
Dependent Claim
22 words
A method according to claim 2 further comprising: queueing transmit units destined for each wireless
station in at least one respective queue.
Claim 13
Dependent Claim
56 words
A method according to claim 1 wherein selecting the
group of wireless stations to compete comprises: on the basis of each wireless station's rate,
determining a next opportunity that each wireless station
should compete for; selecting the group of wireless stations from among
those wireless stations whose rate indicates that should
compete for the particular opportunity.
Claim 14
Dependent Claim
74 words
A method according to claim 2 wherein selecting the
group of wireless stations to compete comprises: queueing transmit units for each wireless station in
either a respective low priority queue or a respective high
priority queue; selecting the group of wireless stations from among
those having transmit units in their high priority queue, and
if none exist, selecting the group of wireless stations from
among those having transmit units in their low priority queue.
Claim 15
Dependent Claim
86 words
A method according to claim 1 wherein the transmit
priority is calculated according to: where: trSize is said transaction size; dFr is said delay parameter; "a" is a timeout value for a given wireless station
which indicates a maximum allowable time which can elapse
before the allocation of a transmit opportunity for the
wireless station; MSPriority is any suitable definition of wireless
station priority; α is an accelerator factor towards a higher priority
for a given wireless station that has not been selected
for a while.
Claim 16
Dependent Claim
108 words
A method according to claim 2 wherein transmit
opportunities are slots transmitted as part of superframes,
each superframe containing a plurality of transmit slots
available for allocation for transmission by one of said
wireless stations, and at least one slot which is reserved,
the method further comprising: setting a timeout value for each wireless station
indicating a time before which the wireless station must
transmit to avoid causing a timeout; if a timeout value for a particular wireless station
will result in the wireless station timing out during a slot
which is reserved, resetting the timeout to occur at a slot
available for allocation before the reserved slot.
Claim 17
Dependent Claim
44 words
A method according to claim 3 further comprising
periodically reserving transmit opportunities for contention
access by wireless stations not currently in competition for
transmit opportunities, the reserved transmit opportunities
being unavailable for allocation for transmission by wireless
stations currently in competition for transmit opportunities.
Claim 18
Dependent Claim
32 words
A method according to claim 1 applied simultaneously
for forward link and reverse link communication with a
respective instance of the method being applied to forward
link communications and reverse link communications.
Claim 19
Dependent Claim
26 words
A method according to claim 18 further comprising: reserving reverse link transmit opportunities for
wireless stations which are simultaneously involved in
reception of forward link traffic.
Claim 20
Dependent Claim
10 words
A scheduler operable to implement the method of
claim 1.
Claim 21
Dependent Claim
11 words
A base station operable to implement the method of
claim 1.
Claim 22
Dependent Claim
12 words
A base station controller operable to implement the
method of claim 1.
Claim 23
Dependent Claim
16 words
A Media Access Control protocol (MAC) layer device operable to
implement the method of claim 1.
Claim 24
Dependent Claim
163 words
An article of manufacture having computer readable
program code means embodied therein for causing selection of
one of a plurality of wireless base stations to be allocated a
particular transmit opportunity, the computer readable code
means in said article of manufacture comprising: computer readable code means for maintaining a respective
transaction length for each wireless station and maintaining a
respective delay parameter for each wireless station
indicative of how long since the wireless station was last
allocated a transmit opportunity; computer readable code means for selecting a group of
said wireless stations to compete for the transmit
opportunity; computer readable code means for each of the group of
said wireless stations, computing a respective transmit
priority which is a function of the respective transaction
length and the respective delay parameter; and computer readable code means for selecting a wireless
station in said group of said wireless stations with the
highest transmit priority as the wireless station to be
allocated the particular transmit opportunity.
References Cited (Backward Citations)
No citation records indexed.
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