Patent Application
20240267313
The present disclosure relates generally to the field of communication networks. Specifically, the present disclosure relates to a device and a method for operating according to a client-server communication protocol in the communication network. The communication protocol may be a Constrained Application protocol (CoAP). The present disclosure also relates to an on-path observer entity and a method for a CoAP communication.
Generally, a CoAP is a specialized web transfer communication protocol for use with constrained nodes and constrained (e.g., low-power, lossy) networks. A reliability of a transmitted message in the CoAP is provided by marking a message as confirmable (CON) with ACKs. A message that does not require a reliable transmission may be sent as a non-confirmable message (NON).
A conventional CoAP protocol is based on a reliable mode CoAP. In the reliable mode of the CoAP, there may be sequence numbers and ACKs, which could eventually be used to measure a Round-Trip Time (RTT) and losses. However, the reliable mode of the CoAP may be resource-consuming for constrained nodes, since the constrained nodes have to look at sequence numbers, and have to obtain timestamps. Performing such operations is resource consuming and therefore expensive. Another conventional CoAP protocol is based on an unreliable mode CoAP. In the unreliable mode of the CoAP, there may be no ACK, and consequently, there may be no possibility to measure the RTT and losses.
One proposed method for measuring loss and delay in the CoAP is based on an Explicit Flow Measurement (EFM) technique. The EFM based method employs a few marking bits, arranged inside the header of each packet, for performing loss and delay measurements. The EFM based method may be used for encrypted protocols, in which there are only a few bits available in the non-encrypted header to allow performance metrics from an on-path observer.
An issue of conventional devices and methods is that substantially complex algorithms are used, which may not be applicable in the CoAP environment.
In view of the above, the present disclosure aims to improve the conventional devices and methods for operating in a communication network, based on a communication protocol such as CoAP.
An objective is to provide a performance measurement method that is simple and straightforward to carry out. For example, the performance measurement method of the present disclosure should operate with limited resources on constrained nodes in the CoAP.
Another objective is to provide constrained application performance metrics. For example, the devices and methods of the present disclosure should facilitate performance measurements for CoAP, e.g., for machine-to-machine (M2M) applications such as Internet of Things (IoT), smart energy, building automation, etc.
Yet another objective is to exploit synergies between different Performance Measurement (Pm) bits, in order to improve the performance measurements. For instance, the disclosure aims at exploiting a synergy between Spin (S) bit and sQuare (Q) bit.
These and other objectives are achieved by the solutions of this disclosure as described in the enclosed independent claims. Advantageous implementations are further defined in the dependent claims.
A first aspect of the present disclosure provides a device for operating according to a client-server communication protocol in a communication network, the device being configured to send to or receive from another device in the communication network, a message comprising a header, the header comprising an option that includes a first Performance Measurement (PM) bit, wherein the first PM bit indicates a first performance parameter and a second performance parameter.
The device may be, or may be implemented in, a client device, a server device, a node, a constrained node, etc. For example, the device may be a constrained node configured to communicate based on CoAP. The constrained node may have limited power, memory, complexity, or the like, without limiting the present disclosure to the CoAP or the nodes in the CoAP. The device may comprise a circuitry. The circuitry may comprise hardware and software. The hardware may comprise analog or digital circuitry, or both analog and digital circuitry. The circuitry may comprise one or more processors and a non-volatile memory connected to the one or more processors. The non-volatile memory may carry executable program code which, when executed by the one or more processors, causes the device to perform the operations or methods described herein.
The device of the first aspect may operate in the CoAP and may use one or more options. In at least one option, it may be possible to encode PM bits. The PM bits may be, for example, a Spin (S) bit, a sQuare (Q) bit, and one or more event signaling bits. The device may (e.g., the client or the server) set the one or more bits.
The device of the first aspect may support measuring performance metrics in a CoAP environment to satisfy the low resources of constrained nodes.
For example, the device may send the message to the other device, or the device may receive the message from the other device. The message in this case comprises the option. The option may specify a range of permissible numbers of bytes, for example, if it has a choice, a sender may represent the integer with as few bytes. For example, the number 0 may be represented with an empty option value (a zero-length sequence of bytes) and the number 1 may be represented by a single byte with the numerical value of 1. Furthermore, the device and/or the other device may process the values in the options, e.g., the 0 or the 1.
In an implementation form of the first aspect, the first PM bit is a Q bit.
For example, the Q bit may indicate a square wave. Every outgoing packet may comprise the Q bit value, which may be initialized to 0 and may be inverted after sending a number of packets (a sQuare Block or simply Q Block). Further, the device may estimate losses by watching a single direction of the traffic flow, and counting the number of packets in each observed Q Block.
For example, the used operations for processing the S bit and the Q bit may be lighter than a conventional measurement, which is based on reading sequence numbers for each packet and by taking timestamps for each packet. Further, the S bit and Q bit may be applied for batch of packets in such a way that the S bit may be used for measuring RTT and one-way delay, and the Q bit may be used for measuring one-way packet loss. Furthermore, it may be possible to choose the node with less constraints.
This may enable equipping the CoAP with performance measurement bits to enable RTT and loss measurements. Hence, it may be possible to provide a simple way to perform performance measurements in a constrained node.
In a further implementation form of the first aspect, the device is further configured to set a value of the first PM bit for the message based on a predefined criterion, for instance, based on a fixed number of data packets of the message.
In a further implementation form of the first aspect, the first performance parameter is a one way packet loss, and wherein the device is further configured to determine the one way packet loss for the message based on the first PM bit.
In a further implementation form of the first aspect, the second performance parameter is a RTT, and wherein the device is further configured to flip the value of the first PM bit of a single packet to an opposite of the value, once per each RTT.
In a further implementation form of the first aspect, the device is further configured to determine a signal to retrieve the estimated RTT for the message based on the first PM bit.
For example, the device may estimate the RTT. This may further enable determining network issues in the communication network. For instance, the signaling of loss and RTT events may be used to signal the network issues to an on-path observer (e.g., network administrator, proxy, and gateway) in the communication network.
In a further implementation form of the first aspect, the option further includes at least one of:
In a further implementation form of the first aspect, wherein the second PM is an S bit.
The S bit may be a single bit signal that toggles once per RTT. Further, the S bit may enable latency monitoring of a connection-oriented communication from intermediate observation points.
For example, the device may be client device or server device. The device may also set the value of the Q bit in both uplink and downlink, in order to measure both directions.
In a further implementation form of the first aspect, the second PM bit has a value of 0 or 1, and wherein the device is further configured to change the value of the second PM bit from 0 to 1 or from 1 to 0, once per each end-to-end RTT.
For example, the device and the other device (e.g., the client and the server) may maintain an internal per-connection spin value (i.e., 0 or 1) used to set the spin bit on outgoing packets. The device and/or the other device may initialize the spin value to 0 when a new connection starts.
In the case of the RTT, the device may be only the client. Further, the other device (i.e., the server device) may reflect based on the same rule, when it sees a flipped value in the S bit.
In a further implementation form of the first aspect ,the one or more event bits are configured to encode at least one of loss information and delay information.
In a further implementation form of the first aspect, determine the one way delay for the one or more event bits, and/or determine the one way packet loss for the message based on the one or more event bits. For example, the device may measure packet loss occurred in any single block between any two points.
Furthermore, the device may support adjusting the timeout values based on the real network performance
In a further implementation form of the first aspect, the communication network is based on a machine-to-machine (M2M) network performing a CoAP communication as the client-server communication protocol, and/or the device is a server or a client and is configured to perform a CoAP communication, and/or the message is a CoAP message.
In a further implementation form of the first aspect, the device is further configured to provide the CoAP message to an on-path observer entity of the CoAP communication.
In a further implementation form of the first aspect, the device is further configured to receive a notification from the on-path observer entity, and adjust a protocol parameter of the CoAP communication based on the first
A second aspect of the disclosure provides an on-path observer entity for a CoAP, communication, the on-path observer entity being configured to receive a CoAP message comprising a header from a device, the header comprising an option that includes a first PM bit, wherein the first PM bit indicates a first performance parameter and a second performance parameter.
The on-path observer entity may be a gateway, or a proxy. Moreover, the on-path observer entity of the second aspect may notify the device (e.g., a client device, a server device, a node, etc.) about the first performance parameter and a second performance parameter.
In an implementation form of the second aspect, the first performance parameter is a one way packet loss and/or the second performance parameter is a RTT, and the on-path observer entity is further configured to adjust a protocol parameter of the CoAP communication based on the first performance parameter and/or based on the second performance parameter, and output a notification to the device, the notification indicating the adjusted protocol parameter of the CoAP communication.
In a further implementation form of the second aspect, wherein the on-path observer entity is or is included in a proxy or a gateway for the CoAP communication.
A third aspect of the disclosure provides a method for operating according to a client-server communication protocol in a communication network, the method comprising sending or receiving a message comprising a header, the header comprising an option that includes a first PM bit, wherein the first PM bit indicates a first performance parameter and a second performance parameter.
In an implementation form of the third aspect, the first PM bit is a Q bit.
In a further implementation form of the third aspect, the method further comprises setting a value of the first PM bit for the message based on a predefined criterion, for instance, based on a fixed number of data packets of the message.
In a further implementation form of the third aspect, the first performance parameter is a one way packet loss, and wherein the method further comprises determining the one way packet loss for the message based on the first PM bit.
In a further implementation form of the third aspect, the second performance parameter is a RTT, and wherein the method further comprises flipping the value of the first PM bit of a single packet to an opposite of the value, once per each RTT.
In a further implementation form of the third aspect, the method further comprises determining a signal to retrieve the estimated RTT for the message based on the first PM bit.
In a further implementation form of the third aspect, the option further includes at least one of:
In a further implementation form of the third aspect, the second PM is an S bit.
In a further implementation form of the third aspect, the second PM bit has a value of 0 or 1, and wherein the method further comprises changing the value of the second PM bit from 0 to 1 or from 1 to 0, once per each end-to-end RTT.
In a further implementation form of the third aspect, the method further comprises encoding by the one or more event bits, at least one of loss information and delay information.
In a further implementation form of the third aspect, the method further comprises determining the one way delay for the one or more event bits, and/or determining the one way packet loss for the message based on the one or more event bits.
In a further implementation form of the third aspect, the communication network is based on a M2M network performing a CoAP communication as the client-server communication protocol, and/or the method is for a server or a client and is configured to perform a CoAP communication, and/or the message is a CoAP message.
In a further implementation form of the third aspect, the method further comprises providing the CoAP message to an on-path observer entity of the CoAP communication.
In a further implementation form of the third aspect, the method further comprises receiving a notification from the on-path observer entity, and adjusting a protocol parameter of the CoAP communication based on the first performance parameter and/or based on the second performance parameter.
The method of the third aspect achieves the advantages and effects described for the device of the first aspect.
A fourth aspect of the disclosure provides a method for an on-path observer entity for a CoAP communication, the method comprising receiving a CoAP message comprising a header from a device, the header comprising an option that includes a first PM bit, wherein the first PM bit indicates a first performance parameter and a second performance parameter.
In an implementation form of the second aspect, the first performance parameter is a one way packet loss and/or the second performance parameter is a RTT, and the method further comprises adjusting a protocol parameter of the CoAP communication based on the first performance parameter and/or based on the second performance parameter, and outputting a notification to the device, the notification indicating the adjusted protocol parameter of the CoAP communication.
In a further implementation form of the fourth aspect, the on-path observer entity is or is included in a proxy or a gateway for the CoAP communication.
The method of the fourth aspect achieves the advantages and effects described for the on-path observer entity of the second aspect.
A fifth aspect of the present disclosure provides a computer program comprising a program code for performing the method according to the third aspect or the fourth aspect or any of their implementation forms.
A sixth aspect of the present disclosure provides a non-transitory storage medium storing executable program code which, when executed by a processor, causes the method according to the third aspect or the fourth aspect or any of their implementation forms to be performed.
It has to be noted that the devices, elements, units and means described in the present application could be implemented in software or hardware elements or any kind of combination thereof. The steps which are performed by the various entities described in the present application, as well as the functionalities described to be performed by the various entities, are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.
The above described aspects and implementation forms will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which
The device 100 may be a client device, a server device, a node, or the like. The communication network 1 may be based on a CoAP communication. For example, the communication 1 may operate according to a CoAP protocol.
The device 100 is configured to send to or receive from another device 110 in the communication network 1, a message 101 comprising a header 102. The header 102 comprises an option that includes a first PM bit. The first PM bit indicates a first performance parameter and a second performance parameter.
The device 100 may comprise processing circuitry (not shown) configured to perform, conduct or initiate the various operations of the device 100 described herein. The processing circuitry may comprise hardware and software. The hardware may comprise analog circuitry or digital circuitry, or both analog and digital circuitry. The digital circuitry may comprise components such as application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), digital signal processors (DSPs), or multi-purpose processors. In one embodiment, the processing circuitry comprises one or more processors and a non-transitory memory connected to the one or more processors. The non-transitory memory may carry executable program code which, when executed by the one or more processors, causes the device 100 to perform, conduct or initiate the operations or methods described herein.
The on-path observer entity 200 may be, for example, a gateway, a proxy, or the like. The CoAP communication 2 may be a communication performed in a communication network 1 based on a CoAP protocol.
The on-path observer entity 200 is configured to receive a CoAP message 201 comprising a header 202 from a device 100 or 110. The message 201 may be the message 101 of
In some implementation forms, the on-path observer entity 200 may be implemented in a proxy for performing a CoAP.
For example, the on-path observer entity 200 may be included in a proxy or a gateway for the CoAP communication 2.
The first performance parameter may be a one way packet loss and/or the second performance parameter may be a RTT. The on-path observer entity 200 may adjust a protocol parameter of the CoAP communication 2 based on the first performance parameter and/or based on the second performance parameter.
The on-path observer entity 200 may further output a notification to the device 100 or the other device 110, the notification indicating the adjusted protocol parameter of the CoAP communication 2. A constrained node may need a simple way to do performance measurements. For example, one bit (e.g., the Q bit 301) or two bits (e.g., the Q bit 301 and the S bit 302) may be used. When using two bits, both mechanisms can be improved. With one bit all relevant measurements are still possible.
By equipping the CoAP communication two with PM bits, one or more of the following benefits may be achieved.
The on-path observer entity 200 may comprise processing circuitry (not shown in
For example, the device 100 may determine a signal to obtain a RTT and a one way packet loss for the message 101 or for the message 201, based on only the first PM bit. That is, in this case the option 300 may include only the first PM bit. For example, the first PM bit may be a Q bit 301, which may be modified to emulate an S bit. The Q bit 301 may be used for creating a square wave of a known length (e.g., 64 packets). The device 100 (or the other device 110) may set the Q bit 301, and may toggle its value (0 or 1) every fixed number of packets. The number of packets can be recognized, and the packet loss can thus be determined (if packet loss occurs). However, also the RTT may be determined based on the Q bit 301 in this case, for example, based on a time interval between determined signal characteristics of the square wave signal of the Q bit 301, wherein these signal characteristics emulate the S bit 302. In this way, the first PM bit is used to exploit a synergy between the Q bit 301 and S bit 302 (similarities of the wave signals generated).
To this end, the header 102 or the header 202 may comprise only the Q bit 301 as mentioned. The Q bit 301 may be used for creating the square waves as shown in
After one RTT, the second packet may come back and may be detected. Hence, by detecting again the second packet 312, the device 100 is able to determine a second time 322 for the RTT. This process may be iteratively performed, wherein during each iteration a new second packet is selected and further detected.
Hence, by measuring the distance between the first packet 311 and the second packet 312, it is possible to measure the RTT. Consequently, the device 100 can measure the RTT, e.g., only based on one PM bit (i.e., only the Q bit 301 emulating the S bit).
Therefore, with one PM bit (e.g., only the Q bit 301), it may be possible to measure loss information, delay information, and also emulate the S bit. The S bit 302 can thus be omitted. For example, the device 100 may set the value of the Q bit to 1, at the first time 321 (emulating an S bit being set to 1). The device 100 may set the value of the Q bit to 0, at the second time 322 (emulating an S bit being set to 0).
Of course, also an additional S bit 302 may be used for determining the RTT. Thus, in a further example, the device 100 may also change the value of an S bit as the second PM bit from 0 to 1 or from 1 to 0, once per each end-to-end RTT. That is, in this case the option 300 may include the Q bit and the S bit. For instance, the S bit 302 may cause one bit to ‘spin’, generating one edge (a transition from 0 to 1 or from 1 to 0) once per end-to-end RTT. The spin bit may be set by both sides (e.g., the device 100 being a client device or the other device 110 being a server device) to the same value, for as long as one round trip lasts and then it toggles the value.
Furthermore, the device 100 may determine the one way delay for the one or more event bits, and/or determine the one way packet loss for the message 101 based on one or more event bits.
The option of the header 102 or 202 may be limited to only two PM bits (e.g., the Q bit 301 and the S bit 302). The option of the header 102 or 202 may indicate the event bits that may be used by the on-path observer 200.
In
In
By providing the PM bits and/or the event bits in the header 102 or 202, the on-path observer 200 may read the event signaling bits may interconnects disjointed CoAP networks. This may enable the on-path observer 200 to communicate with client and server to set some parameters such as timeout based on the network performance. A simplified method may be provided for determining the performance metrics. A well-defined sQuare wave may be used and there may be no need to read sequence numbers, and may further there may be no need to store timestamps.
The method 500 comprises a step 501 of sending or receiving a message 101 comprising a header 102, the header 102 comprising an option that includes a first PM bit, wherein the first PM bit indicates a first performance parameter and a second performance parameter.
The method 600 comprises a step 601 of receiving a CoAP message 201 comprising a header 202 from a device 100, 110, the header 201 comprising an option that includes a first bit, wherein the first PM bit indicates a first performance parameter and a second performance parameter.
The present disclosure has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed disclosure, from the studies of the drawings, this disclosure and the independent claims. In the claims, as well as in the description, the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.
This application is a continuation of International Application No. PCT/CN2021/125074, filed on Oct. 20, 2021, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2021/125074 | Oct 2021 | WO |
| Child | 18638308 | US |
