What are the commands for EPC Class1 Gen2 electronic tags?

Tags and readers that comply with the EPC Class 1 Gen2 (G2) protocol version V109 should have the following characteristics:

1. Label memory partition

Tag memory is divided into four independent Bank blocks: Reserved, EPC, TID, and User.

➣ Reserved：Store Kill Password and Access Password。

➣ EPC: Stores EPC numbers, etc.

➣ TID: Stores tag identification numbers, each TID number should be unique.

➣ User: Stores user-defined data.

In addition, there are also units that are also stored in the Lock status bit of each block.

Second, the status of the label

After receiving continuous wave (CW) irradiation and powering up, the tag can be in one of seven states: Ready, Arbitrate, Reply, Acknowledged, Open, Secured, or Killed.

➣ The Ready state is the state in which the label that has not been inactivated begins to be in after powering on, ready to respond to commands.

➣ The Arbitrate state is mainly used to wait for a response to a command such as a query.

➣ After responding to the Query, enter the Reply state, and then send back the EPC number by responding to the ACK command.

➣ After sending back the EPC number, enter the Accumulated state, which can further respond to Req_RN commands.

➣ Access Password is not set to 0 before you can enter the Open state, where you can read and write.

➣ Only when the Access Password is known can it enter the Secured state and perform operations such as read, write, and lock.

➣ Tags that enter the Killed state will remain unchanged and will never generate a modulated signal to activate the RF field, thus permanently invalidating. The inactivated tag should remain in the Killed state in all environments, and enter the inactivated state when powered on, and the inactivation operation is irreversible.

In order for a label to enter a certain state, a set of legal commands in the appropriate order is generally required, and in turn each command can only be effective if the label is in the appropriate state, and the label will also move to other states after responding to the command.

(UHF LED Illuminated Label)

3. Classification of commands

From the perspective of command architecture and extensibility, it is divided into four categories: Mandatory, Optional, Proprietary, and Custom.

From the perspective of the use function, it is divided into three categories: label Select (selection), Inventory (inventory) and Access (access) commands, in addition, in order to expand the command in the future, different encoding of different lengths is reserved for use.

4. Mandatory commands

Tags and readers that comply with the G2 protocol should support 11 commands:

➣ Select

➣ Query

➣ QueryAdjust

➣ QueryRep

➣ ACK

➣ TO

➣ Req_RN

➣ Read

➣ Write

➣ Kill

➣ Lock

5. Optional command

There are three optional commands for G2 protocol-compliant tags and readers: Access, BlockWrite, and BlockErase.

(Flexible Printable Anti-Transfer Label)

6. Proprietary

Proprietary commands are generally used for manufacturing purposes, such as in-house testing of labels, etc., and such commands should be permanently invalidated after the label leaves the factory.

七、Custom commands

It can be a command defined by the manufacturer itself and open to the user, such as Philips provides BlockLock, ChangeEAS, EASAlarm (EAS) and other commands (EAS is the abbreviation of Electronic Article Surveillance).

8. From a functional point of view: Select command

There is only one option: Select, which is required. Tags have a variety of attributes, based on the standards and policies set by the user, use the Select command to change some attributes and flags to artificially select or delineate a specific tag group, and only they can be inventoried and identified or accessed, which is conducive to reducing conflicts and duplicate identification, and speeding up the recognition speed.

9. From a functional point of view: Inventory commands

There are five items: Query, QueryAdjust, QueryRep, ACK, and NAK, all of which are required.

1. After the tag receives a valid Query command, each tag selected that meets the set criteria will generate a random number (similar to rolling the dice), and each tag with a random number of zero will generate an echo (send back the temporary password RN16, a 16-bit random number) and transfer to the Reply state; Tags that meet other criteria will change certain attributes and flags and thus leave the above tag groups, which can help reduce duplicate identification.

2. After the tag receives a valid QueryAdjust command, each tag will generate a new random number (like rerolling the dice), and the others will be the same as Query.

3. After receiving a valid QueryRep command, the tag only subtracts one from the original random number of each tag in the tag group, and the others are the same as Query.

4. Only a single tag can receive a valid ACK command (using the above-mentioned RN16, or the handle Handle, a 16-bit random number that temporarily represents the identity of the tag, which is a security mechanism), and send it back to the EPC area after receiving it, which is the most basic function of the EPC protocol.

5. After receiving a valid NAK command, the tag will be in the Arbitrate state except for the Ready and Killed states.

10. From a functional point of view: Access commands

There are five required ones: Req_RN, Read, Write, Kill, Lock, and three optional ones: Access, BlockWrite, BlockErase.

1. After receiving a valid Req_RN (with RN16 or Handle) command, the tag sends back a handle or a new RN16, depending on the status

2. After receiving a valid Read(with Handle) command, the tag sends back the error type code, or the content and handle of the required block.

3. After receiving a valid Write (with RN16 & Handle) command, the tag sends back an error type code, or sends back a handle if the write is successful.

4. After the tag receives a valid Kill (with Kill Password, RN16 & Handle) command, it sends back an error type code, or sends back a handle if the deactivation is successful.

5. After receiving the valid Lock(with Handle) command, the tag will send back the error type code, or send back the handle if the lock is successful.

6. After receiving a valid Access (with Access Password, RN16 & Handle) command, the tag sends back the handle.

7. After the tag receives a valid BlockWrite (with Handle) command, it sends back an error type code, or sends back the handle if the block is written successfully.

8. After the tag receives a valid BlockErase (with Handle) command, it sends back an error type code, or sends back the handle if the block is erased successfully.

11. What mechanism does the G2 use to avoid conflict?

As mentioned in the above answer, when more than one label with a random number of zero sends back a different RN16, they will have different RN16 waveforms superimposed on the receiving antenna, which is called collisions, and thus cannot be decoded correctly. There are a variety of anti-collision mechanisms to avoid waveform superposition and distortion, such as trying to make only one tag "speak" at a certain time, and then singling it to identify and write each tag in multiple UHF RFID tags.

The above three Q commands embody G2's anti-collision mechanism: if there are multiple tags with zero random numbers and cannot be decoded correctly, the Q command or combination will be strategically resent to the selected tag group until it can be decoded correctly.

12. How to achieve the uniqueness of the Label Identification Number (TID).

The Tag identifier (TID) is a sign of identity between tags (which can be analogous to the number of a banknote). From a security and anti-counterfeiting point of view, any two G2 labels should not be identical, and the labels should be unique. Each of the four storage blocks of the label has its own usefulness, and some can be rewritten at any time after leaving the factory, only the TID should also be able to play this role, so the TID of the label should be unique.

The manufacturer of the G2 chip should use the Lock command or other means to act on the TID to make it permanently locked, and the manufacturer or relevant organization should ensure that the TID of the appropriate length of each G2 chip is unique, and that there will be no second TID of the same type under any circumstances, even if a G2 tag is in the Killed state and will not be activated for reuse, its TID (still in this tag) will not appear in another G2 tag.

In this way, since the TID is unique, even though the EPC code on the label can be copied to another label, it can also be distinguished by the TID on the label, so that the source can be cleared. This architecture and method are simple and feasible, but care should be taken to ensure the unique logical chain.

The V109 version of the G2 protocol stipulates that only 32-bit is required for TID (including 8-bit allocation class identifier, 12-bit tag mask-designer identifier, 12-bit tag model number). For more bits, such as SNR (serial number), it is Tags may contain rather than should. However, since the EPC number is designed to be used to distinguish a single product, 32-bit is probably not enough, and SNR should be included.

13. Kill command in G2 protocol

The G2 protocol sets the Kill command, and it is controlled by a 32-bit password, and the tag will never generate a modulation signal to activate the RF field after the effective use of the Kill command, thus permanently invalidating. However, the original data may still be in the tag, and if it is not entirely impossible to read them, consider improving the meaning of the Kill command - with the data being erased.

In addition, within a certain period of time, due to the cost of using the G2 label or other reasons, the situation that the label can be recycled and reused will be taken into account (for example, the user wants to use the pallet and box with the label, and the corresponding EPC number and the content of the User area should be rewritten after the content is replaced; It is expensive and inconvenient to replace or reattach the label, etc.), and it is necessary to rewrite the content of the label even if it is permanently locked, because of the influence of different lock states, only using Write or BlockWrite, the BlockErase command may not be able to rewrite the EPC number, User content, or password (for example, the EPC number of the label is locked and cannot be rewritten, or the access of the label is not locked but forgotten). password instead of rewriting the EPC number). This creates a requirement for a simple and straightforward Erase command - except for the TID area and its Lock status bit (the label cannot be overridden after the TID is shipped from the factory), the contents of the EPC number, the reserved area, the User area, and other Lock status bits, even if they are permanently locked, will all be erased for rewriting.

In comparison, the functions of the improved Kill command and the added Erase command are basically the same (including that the Kill Password should be used), but the only difference is that the former Kill command does not generate a modulation signal, so that it can also be considered by the different values of the RFU of the parameters carried by the Kill command.

fourteenWhat if the tag or reader does not support optional (Access) commands?

If the BlockWrite or BlockErase command is not supported, it can be replaced by the Write command (write 16-bit at a time) several times, because erase can be regarded as writing 0, and the block of the former block write and block erase is several times the 16-bit, and other conditions of use are similar.

If the BlockWrite or BlockErase command is not supported, it can be replaced by using the Write command (writing 16-bit at a time) several times, because erasing can be considered as writing 0. The blocks of the former block write and block erase are several times 16-bit, and other usage conditions are similar.

If the Access command is not supported, the tag can enter the Secured state and use the Lock command only when the Access Password is 0. The Access Password can be changed in the Open or Secured state. If the Access Password is locked or permanently locked using the Lock command (pwd-read/write bit is 1, permalock bit is 0 or 1, refer to the attached table), the tag can no longer enter the Secured state and can no longer use the Lock command to change any lock state.

If the Access command is supported, it is possible to use the corresponding commands to freely enter all states. Except for the tag being permanently locked or permanently unlocked and refusing to execute certain commands and being in the Killed state, most commands can be effectively executed.

The device won't charge

Replace the battery or USB cable to charge it and try to turn it on

If you still can't charge and turn on after replacing the battery, it may be that the battery is over-discharged, keep the charging connection with a USB cable, take out the battery and put it back on, repeat 3-4 times to activate the battery, and then charge it for 30 minutes and try to turn it on again

The scanning head does not scan when the light is out

If you suddenly can't scan it during use, it may be that the barcode being scanned and the barcode of the scanner head are the same, and the scanner head setting has been changed inadvertently, you can try to scan other barcodes and feedback the test results to our company

What is the best distance for barcode scanning

The best scanning distance depends on the size of the barcode, the best distance will become longer when the barcode is large, and the best distance will be smaller when the barcode is small, generally the best distance is between 10-15cm

Environmental requirements for RFID products in the UHF band

Metal substances and liquid substances (water) have strong signal interference to UHF (the closer to the antenna tag, the greater the interference), and anti-metal tags can be used in metal environments, but there is no solution for liquid environments

The reason why the RFID electronic tag cannot be read and the factors that affect the reading distance?

With the popularization of the concept of the Internet of Things, we are more interested in using RFID electronic tags to manage fixed assets, generally speaking, a complete set of solutions includes RFID fixed asset management system, RFID printer, RFID tag, RFID reader, etc. As an important part, if there is any problem with RFID electronic tags, it will affect the whole system. The reason why the RFID electronic tag cannot be read

1. RFID electronic tag is damagedRFID electronic tag, there are chips and antennas, if the chip is pressed by external force or high static electricity may fail. antenna, if the RFID signal receiving antenna is damaged, it will also cause failure. Therefore, the RFID electronic tag can not be pressed, damaged or torn. Generally, RFID electronic tags with high requirements will be packaged in plastic cards to avoid damage by external forces

Second, there are interfering objects that affect the RFID electronic tag can not pass through the metal, when the tag is blocked by metal, it will affect the reading distance of the RFID inventory machine, or even can not read at all. At the same time, the radio frequency information of RFID electronic tags is also difficult to penetrate water, and if it is blocked by water, the sensing distance will also be limited. In general, the signal of RFID tags can penetrate non-metallic or non-transparent materials such as paper, wood and plastic, and can carry out penetrating communication. If the use scenario is special, it is necessary to customize anti-metal tags or electronic tags with other characteristics, such as high temperature resistance, waterproof, etc

Third, the reading distance is too far RFID electronic tags according to the production process is different, the application environment is different, the RFID reader is different, the reading distance is not the same, if the reading distance is too far, it will affect the reading effect. Factors affecting the reading distance of RFID electronic tags:

1. It is related to the RFID reader RF power, if the RF power is small, the reading and writing distance is close, on the contrary, if the power is large, the reading distance is far

2. It is related to the gain of the RFID reader antenna, the gain of the reader antenna is small, and the reading and writing distance is close, anyway, the gain is high and the reading distance is long

3. It is related to the degree of coordination between the polarization direction and the relative angle of the RFID tag and the antenna, the direction is consistent and the degree of coordination is high, and the reading and writing distance is far, on the contrary, the reading distance is close if it is not cooperated

4. It is related to the attenuation of the feeder unit, the larger the attenuation, the closer the reading and writing distance, and vice versa, the attenuation decreases and the reading distance is far

5. It is related to the total length of the feeder connecting the reader and the antenna, the longer the feeder, the closer the reading and writing distance, and vice versa, the feeder is short and the reading distance is far

Answers to Lora-related questions

LoRa (Long Range) is a modulation technology that provides a longer communication distance than comparable technologies. Modulation is a variant of Linear Modulated Spread Spectrum (CSS) based on spread spectrum technology, with Forward Error Correction (FEC)

1.) What is LoRa Modulation?

LoRa (Long Range) is a modulation technology that provides a longer communication distance than comparable technologies. Modulation is a variant of Linear Modulated Spread Spectrum (CSS) based on spread spectrum technology, with Forward Error Correction (FEC). LoRa significantly improves reception sensitivity, using the entire channel bandwidth to broadcast a single signal, as with other spread spectrum technologies, resulting in more robust channel noise and insensitivity to frequency shifts due to the use of low-cost crystal oscillators. LoRa can modulate the signal 19.5dB below the noise floor, while most Frequency Shift Keying (FSK) requires a signal power of 8-10dB on the noise floor to modulate properly. LoRa modulation is the physical layer (PHY) that can be used by different protocols and different network architectures – Mesh, Star, point-to-point, and so on.

2.) What is LoRaWAN?

LoRa modulation is a PHY and LoRaWAN is a MAC protocol for high-capacity, long-range, low-power star networks, and the LoRa Alliance is standardizing low-power wide-area networks (LPWANs). The LoRaWAN protocol is optimized for low-power, battery-powered sensors, including different levels of end nodes to optimize the balance between network latency and battery life. It's completely bi-directional, built by security experts to ensure reliability and security. The LoRaWAN architecture also makes it easy to locate moving targets for asset tracking, which is the fastest-growing application of the Internet of Things. Major telecom operators are deploying LoRaWAN as a national network, and the LoRa Alliance is standardizing LoRaWAN to ensure that different national networks are interoperable.

3.) What is a LoRa gateway?

LoRa gateways are designed for long-distance star architectures and are used in LoRaWAN systems. They are multi-channel, multi-modulation transceiver and receiver, multi-channel simultaneous demodulation, and can even be multi-signal demodulation on the same channel at the same time due to the characteristics of LoRa. The gateway uses a different RF device than the end node, with a higher capacity, and acts as a transparent bridge to relay messages between the end device and the central network server. The gateway connects to the network server via a standard IP connection, and the end device communicates wirelessly to one or more gateways using a single hop. Communication between all end nodes is generally bidirectional, but it also supports operations such as multicast functions, software upgrades, wireless transmissions, or other high-volume publishing of messages, which reduces wireless communication time. Depending on the required capacity and installation location (home or tower), there are different gateway versions.

4) What is the LoRaWAN data rate?

For LoRa, the LoRaWAN data rate ranges from 0.3kbps to 11kbps, and the GFSK data rate in Europe is 50kbps. In North America, the FCC limits the minimum data rate to 0.9kbps. To maximize the battery life and overall network capacity of the end device, the LoRaWAN network server manages the data rate and RF output of each end device separately through the Adaptive Data Rate (ADR) algorithm. ADR is critical for high-performance networks and is scalable. In terms of infrastructure, deploying a network with minimal investment and deploying more gateways when additional capacity is needed, ADR will result in higher data rates, which can extend network capacity by a factor of 6 to 8.

5.) What is a LoRa Concentrator?

The terms gateway and concentrator are both used, but they are equivalent components in LoRa systems. In other industries, the definition of gateway and concentrator means different parts.

6.) How does LoRa deal with interference?

The LoRa modem can suppress co-channel GMSK interference up to 19.5dB, or in other words, it can accept a signal that is 19.5dB lower than the interfering signal or floor noise. Because of its strong immunity to interference, the LoRaTM modulation system can be used not only in the frequency bands with high spectrum utilization, but also in hybrid communication networks to extend coverage when the original modulation scheme in the network fails.

7.) What is the LoRa data rate rate?

LoRaWAN defines a specific set of data rates, but the terminal chip or PHY is available in a variety of options. The SX1272 supports data rates from 0.3 to 37.5kbps, and the SX1276 supports 0.018 to 37.5kbps.

8.) What is a LoRa endpoint or point?

The LoRa end node is the part of the LoRa network that senses or controls. They are remotely battery-powered. These end nodes use the LoRaWAN network protocol to establish communication with the LoRa gateway (concentrator or base station).

9.) What is Adaptive Data Rate (ADR)?

ADR is a method that varies the actual data rate to ensure reliable packet delivery, optimal network performance, and capacity scale. For example, nodes close to the gateway use higher data rates (shorter transmission times) and lower output power. Only nodes at very marginal link budgets use the lowest data rate and maximum output power. The ADR method can adapt to changes in network infrastructure and support varying path losses. To maximize the battery life and overall network capacity of the end devices, the LoRa network infrastructure manages the data rate and RF output of each end device separately through the implementation of ADR.

10.) What is the actual Tx power that can be reached on the antenna of a LoRa device?

The output power at the chip pins is +20dBm, and after matching/filtering losses, the power behind the antenna is +19dBm +/-0.5dB. The maximum output power is specified differently in different regions, and the LoRaWAN specification defines different output power in different regions to maximize the link budget.

11.) What is the price of the LoRa solution?

LoRa devices, such as the SX1272 or SX1276, use a lower-cost crystal oscillator. In narrowband technology, an expensive temperature-controlled crystal oscillator is required during RX/TX transceiver to reduce frequency drift. Depending on the volume and functionality, the typical BOM cost of a full endpoint is 2 2 5 dollars. The long transmission distance means that the network infrastructure is simplified, as no trunks are required and the deployment is less expensive. Lower power consumption means lower cost batteries and network maintenance.

12.) What is the process of LoRa Channel Activity Detection (CAD) mode?

CAD is used to detect the presence of a LoRa signal, rather than using a method of accepted signal strength (RSSI) to identify if a signal is present. It is able to distinguish the noise from the LoRa signal that is needed. The CAD process requires two symbols, and if detected by CAD, CAD_Detected interrupt becomes valid and the device is in RX mode to accept the data payload.

13.) Why can't my LoRa device or module output power reach 20dBm?

The +20dBm specification is for the pinout power of the chip. In any RF system, bandpass filters and RF switches have insertion loss characteristics, typically achieving +19dBm on the antenna after matched filtering.

14.) Can the mode be changed frequently between FSK and LoRa modulation?

Yes, no problem. LoRa devices can switch from FSK to LoRa (and vice versa) via a simple SPI register write. There is no impact on the performance and reliability of the equipment. LoRa devices can be configured or reconfigured to any parameters as specified in the data sheet.

15.) If I can't reach +20dBm, how can I solve the output power problem?

1. Please make sure you are connected to the correct pin (PA_Boost) settings for the 20dBm output pin. There are two output ports per band. One is a high-power port called PA_boost, and the other is a high-efficiency port called RFO.

2. Then, detect the software configuration. There are three registers that should be configured correctly: RegPaConfig, RegOcp, and RegPaDac. This means that you should select the correct pins in the software for the appropriate output, and then set the correct values for the power level you need.

3. Confirm that they are consistent with the Semtech reference design in order to design a good PCB layout. This is important for the maximum output power possible.

16.) How does the LoRa system achieve mass production testing?

There are three important parameters to be tested in series production: frequency tolerance, output power, and sensitivity. Frequency and output power are easy to test using a spectrum analyzer. If your signal generator does not produce a single LoRa signal, it is highly recommended to test the sensitivity using FSK mode. There is only one RF link in the chip, and both FSK and LoRa are modulated in the digital domain. RF paths can be misassembled, such as virtual soldering, so verification is important. The digital part of the chip LoRa and FSK modulation is not affected by the assembly, so it is sufficient to test the FSK sensitivity for verification of production test performance.

17.) How to choose the right crystal oscillator for LoRa devices?

Normally, for most designs with a bandwidth of 62.5kHz or higher, a +/- 10ppm XTAL is sufficient. With a bandwidth of less than 62.5kHz, TCXO is highly recommended. For more detailed information on crystal specifications, please refer to the data sheet as well as the LoRa Modem Calculator Tool and Application Note - AN1200.14_XO_Gidance_LoRa_Modulation_STD".

18.) For LoRa bandwidth signals, how do you measure frequency accuracy in LoRa mode?

If you are just for measurements, you can use the Synthesizer TX (FSTX) mode, as listed in the LoRa register table, to generate a CW tone based on the LoRa configuration.

19.) What is the relationship between signal bandwidth (BW), symbol rate (Rs) and data rate (DR)?

Theoretically, Rs=BW/(2^SF), DR= SF*( BW/2^SF)*CR, but we recommend that you use the Semtech LoRa Modem Calculator to evaluate the data rate and transmission time according to different configurations.

20.) How to choose LoRa signal bandwidth (BW), spread spectrum factor (SF) and coding rate (CR)?

LoRaWAN primarily uses a 125kHz signal bandwidth setting, but other proprietary protocols can utilize other signal bandwidth (BW) settings. Changing the BW, SF, and CR also changes the link budget and transmission time, and there is a trade-off between battery life and distance. Use the LoRa modem calculator to evaluate the trade-offs.

21.) What are the steps for fault detection when two SX127x modules from different manufacturers cannot communicate with each other?

First, check the frequency shift caused by the crystal oscillator between the two devices. Bandwidth (BW), center frequency, and data rate are all derived from the crystal frequency. Second, check the software/firmware settings on both sides to ensure that the frequency, bandwidth, spread factor, coding rate, and packet structure are consistent.

22.) In LoRa mode, how is it possible to receive an incorrect packet when cyclic redundancy check (CRC) is enabled?

In LoRa mode, the payload is added to the FIFO even if the CRC is wrong. Before getting a payload, the bit PayloadCrcError must be checked to know that it is complete. In Explicit Header mode, there is a small possibility that a false detection will result in a "clone" packet.

Either the wrong header opens the CrcOn bit, then the payload will be wrong, and the modem will mark it as a PayloadCrcError condition, so the packet will be easily filtered out; Either the wrong header disables the CrcOn bit, in which case the pattern thinks the packet is good. These occasional bad packets will have a random length (extracted from the error header message) and can be easily filtered out by the host, e.g. by seeing the size of the anomaly.

23.) Can I send or receive a payload packet of unlimited length with a LoRa device?

No, the maximum size packet length in LoRa mode is 256 bytes.

24.) How do I use DIOx pins in LoRa mode? Do all DIOx pins have to be connected to the MCU?

When you start designing, check the DIO mapping in both LoRa and FSK modes. You can find DIO mapping information in the SX127x LoRa data sheet. DIO doesn't have the same functionality as the usual (typical) MCU GPIOs. There are special interrupt messages (or clock outputs) that indicate events or chip status, which makes your firmware design easier to implement. Theoretically, you might not connect the DIO pin, so you poll the relevant registers to know the status result. Of course, we recommend connecting DIO as much as possible for the external interrupt function, saving the resource load of the MCU, and can operate in a very low-power mode (when packing, sending or receiving packets, the MCU sleeps).

25.) Why are there two RSSI registers in LoRa mode? What's the difference?

In LoRa mode, both registers, RegPktRssiValue and RegRssiValue, are useful. RegPktRssiValue refers to the packet RSSI level, which is similar to the RSSI in FSK mode (non-LoRa mode).

As you know, LoRa can demodulate packets below the noise floor (PktRssi result), then CurrentRssi is equal to or greater than the noise floor. For more information on how to calculate the values of these two RSSIs, please refer to the Semtech API or the latest LoRa data sheet.

26.) How to calculate the actual bit rate and transmission time of the LoRa system?

Steps (i-V) are listed below:

Calculations are easy by using the LoRa calculator and can be downloaded from the Semtech website

27.) The payload length in LoRa mode can be configured to 256 bytes at any data rate

The SX127x LoRa device has a 256-byte FIFO in LoRa mode. Theoretically, all 256 bytes could be used for TX or RX. However, with a low data rate configuration, the 256-byte payload will have a long transmission time (a few seconds or more), which is not good for fading and high-interference environments. This is not a robust configuration in most environments, so it is recommended that if you want a long payload that uses a low data rate, then the packet can be split into several short packets.

28.) Is LoRa a mesh network, peer-to-peer, or a network?

LoRa itself is a PHY that can be used for all network topologies. Mesh networks extend the range of the network, but at the cost of reduced network capacity, synchronization overhead, and reduced battery life due to synchronization and hop counts. As LoRa's link budget and distance range increase, there is no need to extend the distance with mesh network architecture, so LoRaWAN chooses a star architecture to optimize network capacity, battery life, and easy installation.

29.) Can LoRa use IPv6 and 6LoWPAN?

Yes, LoRa is IPv6 and 6LoWPAN compatible. Actility (LoRa partner) and other partners have implemented 6LoWPAN on top of LoRaWAN.

30.) What is the capacity of a LoRa gateway? How many nodes can be connected to a gateway?

First and foremost, capacity is a consequence of the number of packets received in a given period of time. One SX1301 has 8 channels and can accept close to 1.5 million packets of data per day using the LoRaWAN protocol. So, if your application sends one packet per hour, a single SX1301 gateway can handle about 62,500 end devices.