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| network_protocol_programming_lab:15.3_5_exercise [2020/05/15 11:34] – rathke | network_protocol_programming_lab:15.3_5_exercise [2020/06/11 09:16] (current) – rathke | ||
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| In practice, it is not easy to build such systems. Especially the synchronization problems are hard to takle and introduces a large amount of overhead. To alleviate the synchronization problem, asynchronous frequency hopping systems are introduced. A simple system has been proposed by Texas Instruments (look at). | In practice, it is not easy to build such systems. Especially the synchronization problems are hard to takle and introduces a large amount of overhead. To alleviate the synchronization problem, asynchronous frequency hopping systems are introduced. A simple system has been proposed by Texas Instruments (look at). | ||
| - | In that system, the sender selects an arbitrary frequency from a set of available channels and transmits a packet as usual. But the packet has a huge and very large preamble. The receiver will be sensing | + | In that system |
| - | < | + | The idea behind this system is, that the receiver will sense all channels during the time the sender is transmitting the preamble of the packet. In that case, the receiver is able to always find the frequency the sender is using. In this system, receiver need not to always synchronized with the sender and always finds the channel on which the sender will send its packet. |
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| + | < | ||
| This system has also some drawbacks. E.g. if the receiver detects a signal on a channel, but this signal was not generated by sender (e.g. from an microwave owen). In that case, the receiver is blocked. He will wait receiving a packet, that will never come. But for our purposes this system is best fit for a small project. To implement such system, we will divide it in multiple parts: | This system has also some drawbacks. E.g. if the receiver detects a signal on a channel, but this signal was not generated by sender (e.g. from an microwave owen). In that case, the receiver is blocked. He will wait receiving a packet, that will never come. But for our purposes this system is best fit for a small project. To implement such system, we will divide it in multiple parts: | ||
| - | * Changeing a frequency | + | * [[network_protocol_programming_lab: |
| - | * Sensing a channel | + | * [[network_protocol_programming_lab: |
| - | * Receiving a packet | + | * [[network_protocol_programming_lab: |
| - | * Optimizing | + | * [[network_protocol_programming_lab: |
| + | * [[network_protocol_programming_lab: | ||
| + | * [[network_protocol_programming_lab: | ||
| Each part consists of some exercises. For some exercises you can use previous already done exercises. | Each part consists of some exercises. For some exercises you can use previous already done exercises. | ||
