Energy reservation in power limited networks

1. A method for processing wireless network traffic with varying energy availability, the method comprising:

initializing a first energy level threshold for a network node, wherein the first energy level threshold represents a minimum energy level to transmit a non-critical message;

monitoring an energy level of the network node;

receiving a reservation request to reserve additional energy for processing a critical message having a higher priority of delivery than the non-critical message and specifying a next network node to which the critical message is to be transmitted;

increasing the first energy level threshold by the additional energy to reserve energy for processing the critical message in response to receiving the reservation request;

enabling transmission of the non-critical message in response to the monitored energy level being above the increased first energy level threshold;

suspending transmission of the non-critical message in response to the monitored energy level being below the increased first energy level threshold;

receiving the critical message from a previous network node;

releasing the reserved additional energy to transmit the critical message to the next network node specified by the reservation request;

decreasing the first energy level threshold by the additional energy following the transmission of the critical message;

permitting system functions such that the monitored energy level falls below the first energy level threshold;

suspending the system functions to avoid allowing the monitored energy level to fall below a second energy level threshold; and

reserving energy within the network node in response to receiving the reservation request, wherein reserving energy comprises increasing the second energy level threshold, wherein the second energy level threshold is less than the first energy level threshold.

2. The method of claim 1 , further comprising storing received messages in response to message transmission being suspended.

3. The method of claim 2 , further comprising releasing stored messages in response to message transmission being enabled.

4. A non-transitory computer storage medium having computer executable instructions stored thereon which, when executed by a computer, cause the computer to:

initialize a first energy level threshold for a network node, wherein the first energy level threshold represents a minimum energy level to transmit a non-critical message;

monitor an energy level of the network node within a wireless network;

increase the first energy level threshold by an additional energy to process a critical message having a higher priority of delivery than the non-critical message in response to receiving a reservation request to reserve the additional energy, the reservation request further specifying a next network node to which the critical message is to be transmitted;

enable transmission of the non-critical message in response to the monitored energy level being above the increased first energy level threshold; and

suspend transmission of the non-critical message in response to the monitored energy level being below the increased first energy level threshold;

receive the critical message from a previous network node;

release the reserved additional energy to transmit the critical message to the next network node specified by the reservation request;

decrease the first energy level threshold by the additional energy following the transmission of the critical message;

suspend system functions to avoid allowing the monitored energy level to fall below a second energy level threshold, wherein the second energy level threshold is less than the first energy level threshold; and

reserve energy within the network node in response to receiving the reservation request, wherein reserving energy comprises increasing the second energy level threshold.

5. The computer storage medium of claim 4 , further causing the computer to store received messages in response to message transmission being suspended.

6. The computer storage medium of claim 5 , further causing the computer to release stored messages in response to message transmission being enabled.

7. A wireless network system, the system comprising:

a source network node;

a relay network node;

a destination network node; and

a controller module within the source network node operable to:

establish a delay period representing an estimated time frame utilized by the relay node to build additional energy for relaying a critical message;

transmit a reservation message, wherein the reservation message signals the relay network node to build the additional energy for relaying the critical message in addition to energy for relaying non-critical messages;

wait for the delay period after transmitting the reservation message;

transmit the critical message after waiting for the delay period;

receive an acknowledgement of the critical message within a timeout period;

increase the delay period in response to failing to receive the acknowledgement within the timeout period;

retry the reservation and critical message transmission using the increased delay period in response to failing to receive the acknowledgement within the timeout period;

receive the critical message from a previous network node;

release the additional energy to transmit the critical message to a next network node specified by the reservation message;

decrease a first energy level threshold by the additional energy following the transmission of the critical message;

permit system functions such that the energy level of the relay network node falls below the first energy level threshold;

suspend the system functions to avoid allowing the energy level of the relay network node to fall below a second energy level threshold; and

reserve energy within the relay network node in response to receiving the reservation message, wherein reserving energy comprises increasing the second energy level threshold wherein the second energy level threshold is less than the first energy level threshold.

8. The system of claim 7 , wherein the acknowledgement originates at the destination node.

9. The system of claim 7 , wherein the reservation message further signals a path indicating other network nodes including the destination network node to which the relay network node relays the critical message.

10. The system of claim 7 , wherein the controller module is further operable to:

receive a second acknowledgement of the critical message within the timeout period, wherein the second acknowledgement specifies a new delay period provided by the relay network node; and

increase the delay period to the new delay period specified in the second acknowledgement in response to receiving the second acknowledgement.