Changes for page How to improve LoRaWAN distance
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... ... @@ -4,102 +4,91 @@ 4 4 5 5 6 6 7 -= 1.OverView =7 += OverView = 8 8 9 - 10 10 In real-world deployment for LoRa, distance is a common topic. We always want to have the longest distance. This chapter shows some instructions for how to improve this. 11 11 12 12 12 += Analyze at the software side = 13 13 14 -= 2. Analyzeat the softwareside=14 +== LoRa parameters that effect distance == 15 15 16 -== 2.1 LoRa parameters that effect distance == 17 - 18 - 19 19 Some settings in End Node will affect the transfer distance. They are: 20 20 21 -* (% style="color:blue" %)**TXPower: **(%%)This means the output power from End Node. There is a command [[AT+TXP>>url:http://wiki.dragino.com/xwiki/bin/view/Main/End%20Device%20AT%20Commands%20and%20Downlink%20Command/#H7.14TransmitPower]] can be used to set the output power. TXP parameters follow the LoRaWAN regional document (rp2-1.0.3-lorawan-regional-parameters.pdf). Set to(% style="color:#037691" %)**AT+TXP=0**(%%)is always has the maximum output, but(% style="color:#037691" %)**AT+TXP=0**(%%)has different value in different frequency bands.18 +* **TXPower: **This means the output power from End Node. There is a command [[AT+TXP>>url:http://wiki.dragino.com/xwiki/bin/view/Main/End%20Device%20AT%20Commands%20and%20Downlink%20Command/#H7.14TransmitPower]] can be used to set the output power. TXP parameters follow the LoRaWAN regional document (rp2-1.0.3-lorawan-regional-parameters.pdf). Set to AT+TXP=0 is always has the maximum output, but AT+TXP=0 has different value in different frequency bands. 22 22 23 -* (% style="color:blue" %)**Data Rate(DR): **(%%)This is a combination of Spreading Factor and Band Width. Lowest Data Rate (DR=0) always has the longest transmit distance in LoRaWAN protocol.20 +* **Data Rate(DR): **This is a combination of Spreading Factor and Band Width. Lowest Data Rate (DR=0) always has the longest transmit distance in LoRaWAN protocol. 24 24 25 25 Below is the TXPower and DR table of EU868 Frequency band as reference. 26 26 27 - 28 28 [[image:image-20221006185826-1.png]] 29 29 30 - 31 31 [[image:image-20221006185826-2.png]] 32 32 33 33 34 -Set (% style="color:#037691" %)**AT+TXP=0**(%%) **and**(% style="color:#037691" %)**AT+DR=0**(%%)will always has the longest transmit distance. But note that different frequency band has different TXP and DR coding according to LoRaWAN regional settings. Below is example for EU868, US915 and AS923 compare for example.29 +Set AT+TXP=0 and AT+DR=0 will always has the longest transmit distance. But note that different frequency band has different TXP and DR coding according to LoRaWAN regional settings. Below is example for EU868, US915 and AS923 compare for example. 35 35 36 36 37 - **End node actually value when TXP=0 and DR=0**32 +End node actually value when TXP=0 and DR=0 38 38 39 -(% border="1.5" cellspacing="4" style="background-color:#ffffcc; color:black; width:1002px" %) 40 -|(% style="width:134px" %)**Frequency band**|(% style="width:400px" %)**Output Power in LoRa Module (consider 2dB antenna)**|(% style="width:362px" %)((( 41 -**Spreading Factor(Higher SF can transmit further)** 42 -)))|(% style="width:102px" %)**Band Width** 43 -|(% style="width:134px" %)**EU868**|(% style="width:400px" %)14dBm|(% style="width:362px" %)SF=12|(% style="width:102px" %)125Khz 44 -|(% style="width:134px" %)**US915**|(% style="width:400px" %)20 or 22 dBm (depends on max output of module)|(% style="width:362px" %)SF=10|(% style="width:102px" %)125Khz 45 -|(% style="width:134px" %)**AS923**|(% style="width:400px" %)14dBm|(% style="width:362px" %)SF=12|(% style="width:102px" %)125Khz 34 +| |**Output Power in LoRa Module (consider 2dB antenna)**|((( 35 +**Spreading Factor** 46 46 37 +**(Higher SF can transmit further)** 38 +)))|**Band Width** 39 +|**EU868**|14dBm|SF=12|125Khz 40 +|**US915**|20 or 22 dBm (depends on max output of module)|SF=10|125Khz 41 +|**AS923**|14dBm|SF=12|125Khz 47 47 43 +== Adaptive Data Rate (ADR) and set max distance == 48 48 49 - ==2.2AdaptiveDataRate(ADR)and setmaxdistance==45 +ADR is the feature that Server will ask End Node to adjust the TXP and DR according to some rules in the server. This is for the purpose of Network Management and Optimize End Node battery life-time. 50 50 51 51 52 - **ADR**is the featurethatServer will askEndNodeto adjust the TXP andDR accordingto some rules in the server.Thisis for thepurpose of Network Management and Optimize End Nodebatterylife-time.48 +By default, ADR is turn on(AT+ADR=1) so End node ADR feature is enable. 53 53 54 54 55 - By default,ADR is turnon((%style="color:#037691"%)**AT+ADR=1**)(%%)so End nodeADRfeatureis enable.51 +Normally, user can set the max distance by setting: 56 56 53 +AT+ADR=0 57 57 58 - (% style="color:blue" %)**Normally, user can set the max distance by setting:**55 +AT+DR=0 59 59 60 - (% style="color:#037691" %)**AT+ADR=0**57 +AT+TXP=0 61 61 62 -(% style="color:#037691" %)**AT+DR=0** 63 63 64 -(% style="color:#037691" %)**AT+TXP=0** 65 - 66 - 67 67 This can be downlink via the LoRaWAN downlink command, see [[this link>>url:http://wiki.dragino.com/xwiki/bin/view/Main/End%20Device%20AT%20Commands%20and%20Downlink%20Command/#H8.2UseDownlinkCommandtosetafixuplinkDR]] for reference. 68 68 69 69 70 70 71 -== 2.3Check for short distance problem ==64 +== Check for short distance problem == 72 72 73 - 74 74 According to the above technology, if we have a problem on the distance, we can first check if the end node is trying to longest distance modulation already. We can see that from the LoRaWAN server. Below is an example from Chirpstack. 75 75 76 76 77 -We can see the traffic in gateway 's page and know that the distance is SF12 / BW125. (note, server is not able to know Transmit Power settings from End Node)69 +We can see the traffic in gateway’s page and know that the distance is SF12 / BW125. (note, server is not able to know Transmit Power settings from End Node) 78 78 79 - 80 80 [[image:image-20221006185826-3.png]] 81 81 82 82 83 83 84 -== 2.4Best software settings for the longest distance ==75 +== Best software settings for the longest distance == 85 85 86 - 87 87 Below are the settings for longest distance transmission. ( will reduce battery life) 88 88 89 -* (% style="color:#037691" %)AT+ADR=0(%%)~/~/90 -* (% style="color:#037691" %)AT+DR=(%%)~/~/91 -* (% style="color:#037691" %)AT+TXP=0(%%)~/~/79 +* AT+ADR=0 ~/~/ Disable ADR 80 +* AT+DR=0 ~/~/ Use the smallest DR 81 +* AT+TXP=0 ~/~/ Use max power. 92 92 93 93 94 94 95 -= 3.Installation Guidelines =85 += Installation Guidelines = 96 96 97 -== 3.1Check the use environment ==87 +== Check the use environment == 98 98 99 - 100 100 First , User should notice: Radio link quality and performances are highly dependent of the environment. 101 101 102 - (% style="color:blue" %)**Better performances can be reached with:**91 +Better performances can be reached with: 103 103 104 104 * Outdoor environment. 105 105 * No obstacles. ... ... @@ -106,29 +106,22 @@ 106 106 * No high level radio interferes in the ISM band you use. 107 107 * At least 1 meter above the ground. 108 108 98 +Radio performances are degraded with: 109 109 110 - 111 -(% style="color:blue" %)**Radio performances are degraded with:** 112 - 113 113 * Obstacles: buildings, trees... 114 114 * Inner buildings environments. 115 115 * High ISM band usage by other technologies. 116 116 * Radio communication are usually killed with bad topographic conditions. It is usually not possible to communicate through a hill, even very small. 117 117 105 +== Improve the Antenna == 118 118 119 - 120 -== 3.2 Improve the Antenna == 121 - 122 - 123 123 In some case, we have to install the device inside the chamber or next to a metal case. So the signal between the antenna and the receiver (gateway) is blocked by the metal. This will greatly reduce the signal. In such case, we can consider using antenna extend cable to extend the antenna to a better position. 124 124 125 125 110 += Some real-world case = 126 126 127 -= 4.Some real-worldcase =112 +== Server reason cause end node has problem on Join. == 128 128 129 -== 4.1 Server reason cause end node has problem on Join. == 130 - 131 - 132 132 In one case, the customer is using AWS IoT Core and gateway to connect to AWS via Basic Station Connection, Frequency Band is AU915 sub-band 2. For some unknown reason, AWS always set downlink power to 0dBm, which cause the gateway only emit a very low power and lead to a short distance for sensor. 133 133 134 134 ... ... @@ -140,6 +140,6 @@ 140 140 141 141 The fix of this issue is to set the output power to a high value even server ask to send out 0dBm. 142 142 143 -Reference Link: [[http:~~/~~/wiki.dragino.com/xwiki/bin/view/Main/Change%20Gateway%20Power/#H1.A0Overview>>http://wiki.dragino.com/xwiki/bin/view/Main/Change%20Gateway%20Power/#H1.A0Overview]]125 +Reference Link: 144 144 145 - 127 +http:~/~/wiki.dragino.com/xwiki/bin/view/Main/Change%20Gateway%20Power/#H1.A0Overview