Last modified by Edwin Chen on 2025/01/29 20:30
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From version < 4.4 >
edited by Xiaoling
on 2022/05/11 14:42
To version < 4.1 >
edited by Xiaoling
on 2022/05/11 14:26
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... ... @@ -60,39 +60,17 @@
60 60  
61 61  = 2. Notice of US915/CN470/AU915 Frequency band =
62 62  
63 -(((
64 64  If user has problem to work with lorawan server in band US915/AU915/CN470, he can check:
65 -)))
66 66  
67 -* (((
68 -What **sub-band** the server support ?
69 -)))
70 -* (((
71 -What is the **sub-band** the gateway support ?
72 -)))
73 -* (((
74 -What is the **sub-band** the end node is using ?
75 -)))
65 +* What **sub-band** the server support ?
66 +* What is the **sub-band** the gateway support ?
67 +* What is the **sub-band** the end node is using ?
76 76  
77 -(((
78 78  All of above should match so End Node can properly Join the server and don't have packet lost.
79 -)))
80 80  
81 -(((
82 -
83 -)))
84 -
85 -(((
86 86  In LoRaWAN protocol, the frequency bands US915, AU915, CN470 each includes at least 72 frequencies. Many gateways support only 8 or 16 frequencies, and server might support 8 frequency only. In this case, the OTAA join time and uplink schedule is long and unpredictable while the end node is hopping in 72 frequencies, because the end node will send data in many frequency that the gateway or server doesn,t support.
87 -)))
88 88  
89 -(((
90 -
91 -)))
92 -
93 -(((
94 94  Here are the freuqency tables for these bands as reference:
95 -)))
96 96  
97 97  [[image:https://wiki.dragino.com/images/thumb/3/3f/US915_FRE_BAND-1.png/600px-US915_FRE_BAND-1.png||height="170" width="600"]]
98 98  
... ... @@ -104,23 +104,15 @@
104 104  
105 105  [[image:https://wiki.dragino.com/images/thumb/3/3a/CN470_FRE_BAND-1.png/600px-CN470_FRE_BAND-1.png||height="205" width="600"]]
106 106  
107 -(((
108 108  CN470 Channels
109 -)))
110 110  
111 -(((
112 112  If we look at the [[TTN network server frequency plan>>url:https://www.thethingsnetwork.org/docs/lorawan/frequency-plans.html]], we can see the US915 frequency band use the channel 8~~15.So the End Node must work at the same frequency in US915 8~~15 channels for TTN server.
113 -)))
114 114  
115 115  [[image:https://wiki.dragino.com/images/thumb/9/9a/US915_FRE_BAND-2.png/600px-US915_FRE_BAND-2.png||height="288" width="600"]]
116 116  
117 -(((
118 118  TTN FREQUENCY PLAN
119 -)))
120 120  
121 -(((
122 122  In dragino end node, user can use AT+CHE command to set what frequencies set the end node will use. The default settings for Dragino end node are preconfigure for TTN server, so use 8~~15 channels, which is **AT+CHE=2**. (AT+CHE=1 for first 8 channels, AT+CHE=2 for second 8 channels.. etc, and AT+CHE=0 for all 72 channels. )
123 -)))
124 124  
125 125  
126 126  = 3. Why i see data lost/unperiocially uplink data? Even the signal strength is good =
... ... @@ -131,40 +131,18 @@
131 131  * **Gateway** ~-~-> Use Sub-band2 (Channel 8,9,10,11,12,13,14,15) for Dragino Gateway. this is the default settings for dragino sensors.
132 132  * **LoRaWAN server** ~-~-> ChirpStack default installation and use Sub-band1, **enabled_uplink_channels=[0, 1, 2, 3, 4, 5, 6, 7]** in the file chirpstack-network-server.toml.
133 133  
134 -(((
135 135  When Sensor power on, it will use sub-band2 to join the network, the frequency matches the settings in gateway so all Join Request will be passed to the server for Join. Server will ask the sensor to change to Sub-band1 in the Join Accept downlink message. Sensor will change to sub-band1 for data upload. This cause the sensor and gateway have different frequencies so user see lost of most data or even no data.
136 -)))
137 137  
138 -(((
139 -
140 -)))
141 -
142 -(((
143 143  Use Subband2 as a default subband cause the sensor to have problem to work with the LoRaWAN server which use other subband, and use need to access to the end node to change the subband by console. that is not user frendily,. So since Dragino LoRaWAN Stack version DLS-005(release on end of 2020), we have changed the device to use All Subbands for OTAA join, for example, device will use the first frequency in Sub-Band1 as firt OTAA join packet, then use the first frequency in Sub-Band 2 , then first frequency in sub-band 3, and so on. LoRaWAN server will normally provide the required subband in the OTAA accept process, so end node will know what subband it use after join. If LoRaWAN server doesn't provide subband info in OTAA join, end node will use the subband which join success as the working subband. So the new method cause a longer OTAA Join time but will be compatible with all LoRaWAN server. And new method won't affect the normal uplink after Join Success.
144 -)))
145 145  
146 146  
147 147  = 4. Transmision on ABP Mode =
148 148  
149 -(((
150 150  In ABP mode, there is a Frame Counter Checks. With this check enabled, the server will only accept the frame with a higher counter. If you reboot the device in ABP mode, the device will start from count 0, so you won't be able to see the frame update in server.
151 -)))
152 152  
153 -(((
154 -
155 -)))
156 -
157 -(((
158 158  So in ABP mode, first check if the packet already arrive your gateway, if the packet arrive gatewat but didn't arrive server. Please check if this is the issue.
159 -)))
160 160  
161 -(((
162 -
163 -)))
164 -
165 -(((
166 166  To solve this, disable the Frame Counter Check will solve this issue , or reset the frame counter in the device page.
167 -)))
168 168  
169 169  [[~[~[image:https://wiki.dragino.com/images/thumb/1/19/ABP_Issue-1.jpg/600px-ABP_Issue-1.jpg~|~|height="340" width="600"~]~]>>url:https://wiki.dragino.com/index.php/File:ABP_Issue-1.jpg]]
170 170  
... ... @@ -177,9 +177,7 @@
177 177  
178 178  LoRaWAN End node will open two receive windows to receive the downstream data. If the downstream packets arrive the end node at these receive windows, the end node will be able to get this packet and process it.
179 179  
180 -(((
181 181  Depends on Class A or Class C, the receive windows will be a little difference,
182 -)))
183 183  
184 184  [[image:https://wiki.dragino.com/images/thumb/1/1a/Downstream_LoRaWAN-1.png/600px-Downstream_LoRaWAN-1.png||height="590" width="600"]]
185 185  
... ... @@ -206,9 +206,7 @@
206 206  Set a downstream in TTN and see it is sent
207 207  
208 208  
209 -(((
210 210  This downstream info will then pass to the gateway downstream list. and include the DR which is used (SF9BW125) in EU868 is DR3
211 -)))
212 212  
213 213  [[image:https://wiki.dragino.com/images/thumb/d/dc/Downstream_debug_2.png/600px-Downstream_debug_2.png||height="245" width="600"]]
214 214  
... ... @@ -217,9 +217,7 @@
217 217  
218 218  **For LoRaWAN Gateway**
219 219  
220 -(((
221 221  When the downstream packet appear on the traffic of Gateway page. The LoRaWAN gateway can get it from LoRaWAN server and transmit it. In Dragion Gateway, this can be checked by runinng "logread -f" in the SSH console. and see below:
222 -)))
223 223  
224 224  [[image:https://wiki.dragino.com/images/thumb/2/21/Downstream_debug_3.png/600px-Downstream_debug_3.png||height="195" width="600"]]
225 225  
... ... @@ -232,51 +232,47 @@
232 232  
233 233  (% class="box infomessage" %)
234 234  (((
235 - AT+RX2FQ=869525000 ~-~--> The RX2 Window frequency
177 +AT+RX2FQ=869525000 ~-~--> The RX2 Window frequency
236 236  )))
237 237  
238 238  (% class="box infomessage" %)
239 239  (((
240 - AT+RX2DR=3 ~-~--> The RX2 DataRate
182 +AT+RX2DR=3 ~-~--> The RX2 DataRate
241 241  )))
242 242  
243 243  (% class="box infomessage" %)
244 244  (((
245 - AT+RX1DL=1000 ~-~--> Receive Delay 1
187 +AT+RX1DL=1000 ~-~--> Receive Delay 1
246 246  )))
247 247  
248 248  (% class="box infomessage" %)
249 249  (((
250 - AT+RX2DL=2000 ~-~--> Receive Delay 2
192 +AT+RX2DL=2000 ~-~--> Receive Delay 2
251 251  )))
252 252  
253 253  when the device running, we can see below info:
254 254  
255 -(% class="box" %)
256 -(((
257 - [12502]~*~*~*~** UpLinkCounter= 0 ~*~*~*~**
258 - [12503]TX on freq 868500000 Hz at DR 0
259 - [13992]txDone
260 - [15022]RX on freq 868500000 Hz at DR 0     ~-~-> RX1 window open at frequency: 868500000, DR0, after 15022-13992= 1030ms of txdone
261 - [15222]rxTimeOut                           ~-~-> no packet arrive in RX1 window. (duration: 200ms)
262 - [15987]RX on freq 869525000 Hz at DR 3     ~-~-> RX2 window open at frequency: 869525000, DR3, after 15987-13992= 1995ms of txdone
263 - [16027]rxTimeOut                           ~-~-> no packet arrive in RX2 window. (duration: 40 ms)
264 -)))
197 +{{{[12502]***** UpLinkCounter= 0 *****
198 +[12503]TX on freq 868500000 Hz at DR 0
199 +[13992]txDone
200 +[15022]RX on freq 868500000 Hz at DR 0 --> RX1 window open at frequency: 868500000, DR0, after 15022-13992= 1030ms of txdone
201 +[15222]rxTimeOut --> no packet arrive in RX1 window. (duration: 200ms)
202 +[15987]RX on freq 869525000 Hz at DR 3 --> RX2 window open at frequency: 869525000, DR3, after 15987-13992= 1995ms of txdone
203 +[16027]rxTimeOut --> no packet arrive in RX2 window. (duration: 40 ms)
204 +}}}
265 265  
266 -(% class="box" %)
267 -(((
268 - Another message:
269 - [12502]~*~*~*~** UpLinkCounter= 0 ~*~*~*~**
270 - [12503]TX on freq 868100000 Hz at DR 0
271 - [13992]txDone
272 - [15022]RX on freq 868100000 Hz at DR 0
273 - [15222]rxTimeOut
274 - [15987]RX on freq 869525000 Hz at DR 3
275 - [16185]rxDone                              ~-~-> We have got the downstream packet.
276 - Rssi= -64
277 - Receive data
278 - 1:0012345678
279 -)))
206 +{{{Another message:
207 +[12502]***** UpLinkCounter= 0 *****
208 +[12503]TX on freq 868100000 Hz at DR 0
209 +[13992]txDone
210 +[15022]RX on freq 868100000 Hz at DR 0
211 +[15222]rxTimeOut
212 +[15987]RX on freq 869525000 Hz at DR 3
213 +[16185]rxDone --> We have got the downstream packet.
214 +Rssi= -64
215 +Receive data
216 +1:0012345678
217 +}}}
280 280  
281 281  == 5.3 If problem doesn’t solve ==
282 282  

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