Contention-based co-existence on a shared communication medium
Techniques for managing contention on a shared communication medium are disclosed. Various techniques are provided to facilitate aspects such as reference signaling, downlink medium access, uplink medium access, resource reuse, channel structures, acknowledgment schemes, fairness, acquisition, random access, paging, mobility, inter-operator mitigation, and so on for a frame structure implemented on the shared communication medium.
1. A communication method, comprising:
contending for access to a communication medium for a first transmission opportunity (TXOP) spanning a first duration;
transmitting a first channel reservation message reserving the communication medium for the first TXOP;
transmitting during the first TXOP a scheduling grant to an access terminal granting the access terminal uplink resources for a second TXOP spanning a second duration;
contending for access to the communication medium for the second TXOP;
transmitting a second channel reservation message reserving the communication medium for the second TXOP; and
receiving uplink signaling from the access terminal over the granted uplink resources during the second TXOP.
2. The method of claim 1 , wherein the scheduling grant configures the access terminal to:
ignore any uplink subframes scheduled for an intervening time period between the first duration and the second duration, wherein access to the communication medium is yielded during the intervening time period;
carryover the granted uplink resources to an uplink subframe during the second TXOP;
transmit during the second TXOP in response to reception of the second channel reservation message.
3. The method of claim 1 , wherein the transmitting comprises broadcasting the scheduling grant over a common control channel.
4. The method of claim 1 , further comprising retransmitting, during the first TXOP, the scheduling grant to the access terminal.
5. The method of claim 4 , wherein the scheduling grant is transmitted in a first downlink subframe of the first TXOP and retransmitted in a second downlink subframe of the first TXOP.
6. A communication apparatus, comprising:
at least one processor;
at least one memory coupled to the at least one processor, the at least one processor and the at least one memory being configured to contend for access to a communication medium for a first transmission opportunity (TXOP) spanning a first duration; and
at least one transceiver configured to:
transmit a first channel reservation message reserving the communication medium for the first TXOP; and
transmit during the first TXOP a scheduling grant to an access terminal granting the access terminal uplink resources for a second TXOP spanning a second duration
wherein the at least one processor and the at least one memory are further configured to contend for access to the communication medium for the second TXOP; and
wherein the at least one transceiver is further configured to:
transmit a second channel reservation message reserving the communication medium for the second TXOP; and
receive uplink signaling from the access terminal over the granted uplink resources during the second TXOP.
7. The apparatus of claim 6 , wherein the scheduling grant configures the access terminal to:
ignore any uplink subframes scheduled for an intervening time period between the first duration and the second duration, wherein access to the communication medium is yielded during the intervening time period;
carryover the granted uplink resources to an uplink subframe during the second TXOP; and
transmit during the second TXOP in response to reception of the second channel reservation message.
8. The apparatus of claim 6 , wherein the at least one transceiver is further configured to broadcast the scheduling grant over a common control channel.
9. The apparatus of claim 6 , wherein the at least one transceiver is further configured to retransmit, during the first TXOP, the scheduling grant to the access terminal.
10. The apparatus of claim 9 , wherein the at least one transceiver is further configured to transmit the scheduling grant in a first downlink subframe of the first TXOP and to retransmit the scheduling grant in a second downlink subframe of the first TXOP.
11. A communication method, comprising:
receiving a first channel reservation message reserving the communication medium for a first transmission opportunity (TXOP) spanning a first duration;
receiving a scheduling grant from an access point during the first TXOP, wherein the scheduling grant grants uplink resources for a second TXOP spanning a second duration;
identifying uplink resources corresponding to the scheduling grant in the second TXOP;
receiving a second channel reservation message reserving the communication medium for the second TXOP; and
transmitting uplink signaling to the access point over the identified uplink resources during the second TXOP.
12. The method of claim 11 , further comprising:
ignoring any uplink subframes scheduled for an intervening time period between the first duration and the second duration, wherein access to the communication medium is yielded during the intervening time period;
carrying over the granted uplink resources to an uplink subframe during the second TXOP; and
transmitting the uplink signaling during the second TXOP in response to reception of the second channel reservation message.
13. The method of claim 11 , wherein the receiving comprises receiving the scheduling grant over a common control channel.
14. The method of claim 11 , further comprising receiving, during the first TXOP, a retransmission of the scheduling grant from the access point.
15. The method of claim 14 , wherein the scheduling grant is received in a first downlink subframe of the first TXOP and the retransmission of the scheduling grant is received in a second downlink subframe of the first TXOP.
16. The method of claim 11 , further comprising:
identifying uplink resources corresponding to the scheduling grant in the first TXOP; and
transmitting uplink signaling to the access point over the identified uplink resources during the first TXOP.
17. A communication apparatus, comprising:
at least one transceiver configured to:
receive a first channel reservation message reserving the communication medium for a first transmission opportunity (TXOP) spanning a first duration; and
receive a scheduling grant from an access point during the first TXOP, wherein the scheduling grant grants uplink resources for a second TXOP spanning a second duration;
at least one memory coupled to the at least one processor, the at least one processor and the at least one memory being configured to identify uplink resources corresponding to the scheduling grant in the second TXOP,
wherein the at least one transceiver is further configured to:
receive a second channel reservation message reserving the communication medium for the second TXOP; and
transmit uplink signaling to the access point over the identified uplink resources during the second TXOP.
18. The apparatus of claim 17 , wherein the at least one processor and the at least one memory are further configured to:
ignore any uplink subframes scheduled for an intervening time period between the first duration and the second duration, wherein access to the communication medium is yieled during the intervening time period;
carryover the granted uplink resources to an uplink subframe during the second TXOP; and
transmit the uplink signaling during the second TXOP in response to reception of the second channel reservation message.
19. The apparatus of claim 17 , wherein the at least one transceiver is further configured to receive the scheduling grant over a common control channel.
20. The apparatus of claim 17 , wherein the at least one transceiver is further configured to receive, during the first TXOP, a retransmission of the scheduling grant from the access point.
21. The apparatus of claim 20 , wherein the at least one transceiver is further configured to receive the scheduling grant in a first downlink subframe of the first TXOP and to receive the retransmission of the scheduling grant in a second downlink subframe of the first TXOP.
22. The apparatus of claim 17 , wherein:
the at least one processor and the at least one memory are further configured to identify uplink resources corresponding to the scheduling grant in the first TXOP; and
the at least one transceiver is further configured to transmit uplink signaling to the access point over the identified uplink resources during the first TXOP.