- 1. *Invalid Packet Shutdown:*
- Typically, packets are filtered out by address at the radio hardware
- level. When a receiver wakes up and does not receive any
- packets into the low power listening layer of the radio stack, it
- will automatically go back to sleep after some period of time. As a
- secondary backup, if address decoding on the radio chip is disabled,
- the low power listening implementation will shut down the radio if
- three packets are receive that do not belong to the node. This helps
- prevent against denial of sleep attacks or the typical transmission
- behavior found in an ad-hoc network with many nodes.
-
- 2. *Early Transmission Completion:*
- A transmitter typically sends a packet for twice the amount of time
- as the receiver's receive check period. This increases the probability
- that the receiver will detect the packet. However, if the transmitter receives
- an acknowledgement before the end of its transmission period, it
- will stop transmitting to save energy. This is an improvement
- over previous low power listening implementations, which transmitted
- for the full period of time regardless of whether the receiver has
- already woken up and received the packet.
-
- 3. *Auto Shutdown:*
- If the radio does not send or receive messages for some period of
- time while low power listening is enabled, the radio will automatically
- turn off and begin duty cycling at its specified duty cycle period.
-
- 4. *CCA Sampling Strategy:*
- The actual receive check is performed in a loop inside a function,
- not a spinning task. This allows the sampling to be performed
- continuously, with the goal of turning the radio off as quickly as
- possible without interruption.
+1. Invalid Packet Shutdown
+ Typically, packets are filtered out by address at the radio hardware
+ level. When a receiver wakes up and does not receive any
+ packets into the low power listening layer of the radio stack, it
+ will automatically go back to sleep after some period of time. As a
+ secondary backup, if address decoding on the radio chip is disabled,
+ the low power listening implementation will shut down the radio if
+ three packets are receive that do not belong to the node. This helps
+ prevent against denial of sleep attacks or the typical transmission
+ behavior found in an ad-hoc network with many nodes.
+
+2. Early Transmission Completion
+ A transmitter typically sends a packet for twice the amount of time
+ as the receiver's receive check period. This increases the probability
+ that the receiver will detect the packet. However, if the transmitter receives
+ an acknowledgement before the end of its transmission period, it
+ will stop transmitting to save energy. This is an improvement
+ over previous low power listening implementations, which transmitted
+ for the full period of time regardless of whether the receiver has
+ already woken up and received the packet.
+
+3. Auto Shutdown
+ If the radio does not send or receive messages for some period of
+ time while low power listening is enabled, the radio will automatically
+ turn off and begin duty cycling at its specified duty cycle period.
+
+4. CCA Sampling Strategy
+ The actual receive check is performed in a loop inside a function,
+ not a spinning task. This allows the sampling to be performed
+ continuously, with the goal of turning the radio off as quickly as
+ possible without interruption.