Network Term

What is NB-IoT?

Narrow band Internet of Things (NB-IoT) is a cellular technology that limits the bandwidth to 180 kHz. It can be used directly on a GSM, UMTS, or LTE network to reduce the cost and enable smooth upgrades. NB-IoT ensures long battery life and efficient connections of devices that have high network requirements.

What are the disadvantages of NB-IoT communications?

Expensive, complex deployment, and low bandwidth

How is the NB-IoT network latency?

The NB-IoT network latency is about 10s. However, in an environment with the maximum coupling loss, the NB-IoT network latency is about 6s.

How many connected users and activated users does an NB-IoT base station support?

NB-IoT improves the uplink capacity by 50 to 100 times when compared with 2G, 3G, or 4G. Under the same base station, NB-IoT can provide 50 to 100 times connections than existing wireless technologies. The simulated data shows that a single base station cell can support 50,000 NB-IoT terminals when the frequency is 200 kHz.

What is the coverage area of an NB-IoT base station?

An NB-IoT base station improves the gain by 20 dB when compared with LTE and GPRS base stations and is expected to cover places where signals are difficult to reach, such as underground garages, basements, and underground pipelines. The simulated data shows that the covering power of NB-IoT can reach 164 dB in independent deployment mode. The covering power of NB-IoT in in-band deployment and guard band deployment needs to be tested.

What are the advantages of NB-IoT?

1. Wide coverage: NB-IoT optimizes indoor coverage. In the same frequency band, NB-IoT improves the gain by 20 dB and expands the coverage area by 100 times when compared with existing networks.

2. Large number of connections: One sector of an NB-IoT network can support tens of thousands of connections.

3. Low power consumption: An NB-IoT module has a standby time of several years.

4. Low module costs

The NB-IoT RF bandwidth is 200 kHz. The downlink rate is between 160 kbit/s and 250 kbit/s. The uplink rate is between 160 kbit/s and 250 kbit/s (multi-tone) or 200 kbit/s (single-tone).

What are the three NB-IoT working modes?

  1. DRX: indicates discontinuous reception. However, to hardware products, it is continuous reception. Data can be received at anytime. The DRX mode has the highest power consumption. The standby power consumption is about 1 mA.

  2. eDRX: indicates that the network is connected for a while and disconnected for a while. When the network is connected, data can be received. When the network is disconnected, data cannot be received. The network interruption time is configurable, ranging from 10s to several hours. In eDRX mode, the standby power consumption is about 0.2 mA when the network interruption interval is 5 minutes.

  3. PSM mode: The network is disconnected at several days intervals. When the network is connected, data can be received. When the network is disconnected, data cannot be received. In PSM mode, the standby power consumption is microampere-level, and a battery can be used for five years.

What is LoRa?

Long Range (LoRa) is a low-power wide-area network (LPWAN) technology. Under the same power consumption, the LoRa transmission range is three to five times that of a conventional RF transmission technology.

What is SIG?

The Bluetooth Special Interest Group (Bluetooth SIG) is a Bluetooth standards organization that aims to drive the development of the Bluetooth technology. Only Bluetooth SIG certified devices can use the Bluetooth word mark and logo.

What is Bluetooth 5.0?

Bluetooth 5.0 is a Bluetooth technical standard proposed by the Bluetooth Special Interest Group in 2016. Bluetooth 5.0 improves the speed of devices with a low power consumption. Bluetooth 5.0 combined with Wi-Fi assists in positioning indoor locations, increases the transmission speed, and extends the effective working distance.

What is the correct term for "Bluetooth mesh"?

1. For the previous private Tuya Bluetooth mesh, the name has been changed from BLE mesh to Tuya mesh. 2. For the new standard mesh, the name has been changed from SIG Mesh to BLE mesh in English and "蓝牙mesh" in Simplified Chinese.

What is Bluetooth Mesh defined by Bluetooth SIG?

Bluetooth Mesh is a computer mesh networking standard defined by Bluetooth Special Interest Group (Bluetooth SIG).

Bluetooth Mesh is a common standard open to the public. Apart from Bluetooth Mesh, Tuya uses some private protocols.

What is the Bluetooth mesh protocol?

The Bluetooth mesh protocol is a many-to-many (M2M) communication protocol based on Bluetooth. Devices that support the Bluetooth mesh protocol also support Bluetooth 4.0 and 5.0 and can communicate with other devices that support Bluetooth 4.0, such as mobile phones and computers.

What is BLE Mesh?

Bluetooth mesh is a communication method, which is based on the traditional Bluetooth mesh communication. There is no subordinate relationship between devices, and everyone yells at each other to broadcast. If the mobile phone is connected to a Bluetooth mesh device, after the mobile phone sends a command, it can be heard within 10 meters of the vicinity. After hearing it, it will be transmitted to the device within 10M of the device, and then passed on in turn. The instruction will either be transmitted after being heard, or it will not be heard, and no part of it will be lost. In theory, compared with WiFi communication, more devices can be accepted.

What are the advantages of Sigmesh?

1. Bluetooth Alliance (SIG) international standard protocol to achieve true interconnection;

2. Low power consumption technology of micro-amp level;

3. At the same time support mobile phone Bluetooth direct connection control and gateway remote control;

4. Local scene linkage, used in high-end lighting;

5. Suitable for commercial lighting and large-scale group control;

6. The scheme has been certified by the Bluetooth Alliance;

7. Super cost-effective lighting solution;

8. Simple and easy operation, flexible networking, high robustness, and more robust system;

9. Frequency hopping technology, not easily interfered by 2.4GHz frequency communication.

What are the applicable scenarios of SIG mesh?

SIG mesh is suitable for commercial lighting, low-power consumption electrical engineering, and sensors because it has long transmission distance and low power consumption.

The coverage of SIG mesh is three hops by default. What does it mean?

An issued command can pass through three nodes at most. For example, a gateway is connected to device a, which is connected to device b. Device b is connected to device c. The command issued by the gateway goes through devices a and b and stops at device c.

What are the limitations of SIG mesh?

  1. It may cause network congestion.

  2. Without a gateway, it cannot implement remote control. 3. SIG mesh has weak wall penetration performance.

What is Zigbee 3.0?

Zigbee 3.0 is the integration of Zigbee application standards for different vertical industries. It defines the basic device behavior (BDB) of all devices in the Zigbee Pro network. The device network environment, the initial process, the debugging process, device security process, unified application space supported, optimized network properties provided and with forward and backward compatibility.

What is a Zigbee module's high-power firmware?

High-power firmware is used for mains-powered products, which do not typically need low power consumption.

What are the advantages and disadvantages of Zigbee compared to Z-Wave?

Z-Wave is a wireless networking specification dominated by the Danish company Zensys. Z-Wave is an emerging short-range wireless communication technology based on radio frequency, low cost, low power consumption, high reliability and suitable for networks. The working frequency band is 908.42MHz, and the effective coverage of the 868.42MHz signal is 30m indoors and more than 100m outdoor, which is suitable for narrow bandwidth applications. Z-Wave technology is also a low-power and low-cost technology that strongly promotes low-rate wireless personal area networks.

What are the disadvantages of Zigbee?

Expensive, depending on a gateway for control, and low transmission rate.

What is a Zigbee module's low-power firmware?

A Zigbee module with low-power firmware has the scheduled hibernation feature. The module or MCU needs to awaken the peer before sending data.

What is Wi-Fi mesh?

The Wi-Fi mesh protocol is a many-to-many (M2M) communication protocol based on Wi-Fi.

What are the advantages and disadvantages of the Wi-Fi, Bluetooth, and Zigbee protocols?

Wi-Fi is a global unified standard that enables standard Wi-Fi devices to work anywhere in the world. However, Wi-Fi devices have large power consumption and poor networking capabilities. Bluetooth supports complex networks, star topology, and one-to-many connections and is secure. However, Bluetooth has low version compatibility and poor networking capability. It applies to networks with a limited number of nodes, and is not suitable for multi-node control. Zigbee features low-power, large network capacity, and flexible working frequency bands. However, it has a low data transmission rate, small coverage scope, and poor anti-interference performance, and is not open source.

What are the disadvantages of 5 GHz signals?

5 GHz signals have a high frequency, large attenuation over air or through obstacles, and smaller transmission distance than 2.4 GHz signals.

What are the benefits of 5 GHz signals?

5 GHz signals have a wide frequency band, less interference, a stable network speed, and support a high wireless speed.

What is the attenuation formula for the 2.4 GHz frequency?

L1 = 100 + 20lgD

What are the disadvantages of 2.4 GHz signals?

2.4 GHz signals have a narrow frequency band and incur greater interference because most home appliances and wireless devices use 2.4 GHz frequencies.

What are the benefits of 2.4 GHz signals?

2.4 GHz signals have a low frequency, small attenuation over air or through obstacles, and a long transmission distance.

How is the wall penetration effect of 2.4 GHz signals?

2.4 GHz signals have a better wall penetration effect than 5 GHz signals.

Will the network speed be affected if 5 GHz signals are weaker than 2.4 GHz signals?

Yes, theoretically.

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