HCIA-5G新技术融合创新应用
souce: 华为HCIA-5G V2.0
date: 2021-11-21
老师以念PPT为主，笔记主要扩展了解物联网技术。其他如云计算、大数据、AI和应用案例等没有太多深入内容，略。
文章目录
- 1 物联网新技术的特征与现状
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- 1.1 短距无线技术
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- 1.1.1 Bluetooth蓝牙(bluetooth.com)
- 1.1.2 Wi-Fi (Wi-Fi Alliance, wi-fi.org，数字编号命名)
- 1.1.3 ZigBee(ZigBee Alliance, zigbeealliance.org. Now CSA，Connectivity Standards Alliance, csa-iot.org，物联网，与GPL冲突)
- 1.1.4 Z-Wave (z-wavealliance.org)
- 1.2 长距无线技术
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- 1.2.1 SigFox ("0G Network")
- 1.2.2 LoRa (Semtech公司主导，用户量最大)
- 1.2.3 NB-IoT
- 1.2.4 eMTC
- 1.2.5 关于 LoRaWAN 和窄带物联网的 10 件事(https://blog.semtech.cn/title-10-things-about-lorawan-nb-iot)
- 1.3 NB-IoT
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- 1.3.1 NB-IoT解决方案总体架构
- 1.3.2 NB-IoT关键特性
- 1.4 Other Views
1 物联网新技术的特征与现状
1.1 短距无线技术
1.1.1 Bluetooth蓝牙(bluetooth.com)
Origin of the Bluetooth Name, bluetooth.com
- Bluetooth Classic(无线音频流传输)
The Bluetooth Classic radio, also referred to as Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR), is a low power radio that streams data over 79 channels in the 2.4GHz unlicensed industrial, scientific, and medical (ISM) frequency band. Supporting point-to-point device communication, Bluetooth Classic is mainly used to enable wireless audio streaming and has become the standard radio protocol behind wireless speakers, headphones, and in-car entertainment systems. The Bluetooth Classic radio also enables data transfer applications, including mobile printing.
- Bluetooth Low Energy (LE)（低电力、Mesh组网、定位）
The Bluetooth Low Energy (LE) radio is designed for very low power operation. Transmitting data over 40 channels in the 2.4GHz unlicensed ISM frequency band, the Bluetooth LE radio provides developers a tremendous amount of flexibility to build products that meet the unique connectivity requirements of their market. Bluetooth LE supports multiple communication topologies, expanding from point-to-point to broadcast and, most recently, mesh, enabling Bluetooth technology to support the creation of reliable, large-scale device networks. While initially known for its device communications capabilities, Bluetooth LE is now also widely used as a device positioning technology to address the increasing demand for high accuracy indoor location services. Initially supporting simple presence and proximity capabilities, Bluetooth LE now supports Bluetooth Direction Finding and soon, high-accuracy distance measurement.
- parameter comparison (LE版本Mesh组网和定位功能)
| Bluetooth Low Energy (LE) | Bluetooth Classic | |
|---|---|---|
| Frequency Band | 2.4GHz ISM Band | 2.4GHz ISM Band |
| Channels | 40 channels with 2 MHz spacing | 79 channels with 1 MHz spacing |
| Channel Usage | Frequency-Hopping Spread Spectrum (FHSS) | Frequency-Hopping Spread Spectrum (FHSS) |
| Modulation | GFSK | GFSK, π/4 DQPSK, 8DPSK |
| Data Rate | LE 2M PHY: 2 Mb/s | EDR PHY (8DPSK): 3 Mb/s |
| LE 1M PHY: 1 Mb/s | EDR PHY (π/4 DQPSK): 2 Mb/s | |
| LE Coded PHY (S=2): 500 Kb/s | BR PHY (GFSK): 1 Mb/s | |
| Communication Topologies | Point-to-Point | Point-to-Point |
| Broadcast | ||
| Mesh | ||
| Positioning Features | Presence (Advertising) | None |
| Proximity (RSSI, Received Signal Strength Indicator) | ||
| Direction (AoA/AoD, angle of arrival, angle of departure) | ||
| Distance (Coming) |
1.1.2 Wi-Fi (Wi-Fi Alliance, wi-fi.org，数字编号命名)
Wi-Fi technology, based on the Institute of Electrical and Electronics Engineers (IEEE) wireless communication standard 802.11, with each generation bringing faster speeds, lower latency, and better user experiences. To help users identify devices that provide the latest Wi-Fi experience, Wi-Fi Alliance introduced simplified generational names that may appear in device names and product descriptions. The current generation of Wi-Fi, based on the IEEE 802.11ax standard, is known as Wi-Fi 6, which includes devices that can operate in the 6 GHz band, referred to as Wi-Fi 6E.
| Generation/IEEE Standard | Maximum Linkrate | Adopted | Frequency |
|---|---|---|---|
| Wi‑Fi 6E (802.11ax) | 600 to 9608 Mbit/s | 2020 | 6 GHz |
| Wi‑Fi 6 (802.11ax) | 600 to 9608 Mbit/s | 2019 | 2.4/5 GHz |
| Wi‑Fi 5 (802.11ac) | 433 to 6933 Mbit/s | 2014 | 5 GHz |
| Wi‑Fi 4 (802.11n) | 72 to 600 Mbit/s | 2008 | 2.4/5 GHz |
| (Wi-Fi 3)* 802.11g | 6 to 54 Mbit/s | 2003 | 2.4 GHz |
| (Wi-Fi 2)* 802.11a | 6 to 54 Mbit/s | 1999 | 5 GHz |
| (Wi-Fi 1)* 802.11b | 1 to 11 Mbit/s | 1999 | 2.4 GHz |
| (Wi-Fi 0)* 802.11 | 1 to 2 Mbit/s | 1997 | 2.4 GHz |
1.1.3 ZigBee(ZigBee Alliance, zigbeealliance.org. Now CSA，Connectivity Standards Alliance, csa-iot.org，物联网，与GPL冲突)
- Zigbee is the complete loT solution — from mesh network to the universal language that allows smart objects to work together. Zigbee certified products can connect and communicate using the same IoT language with each other, and millions of Zigbee products already deployed in smart homes and buildings.
- Zigbee Alliance is a group of companies that maintain and publish the Zigbee standard. The name Zigbee is a registered trademark of this group, and is not a single technical standard. The relationship between IEEE 802.15.4 and Zigbee is similar to that between IEEE 802.11 and the Wi-Fi Alliance. The requirements for membership in the Zigbee Alliance cause problems for free-software developers because the annual fee conflicts with the GNU General Public Licence. The requirements for developers to join the Zigbee Alliance also conflict with most other free-software licenses. As of May 11, 2021, the Zigbee Alliance has been rebranded to Connectivity Standards Alliance (CSA).
- Technical specifications
| Solution | Description |
|---|---|
| Network Protocol | Zigbee PRO 2015 (or newer) |
| Network Topology | Self-Forming, Self-Healing MESH |
| Network Device Types | Coordinator (routing capable), Router, End Device, Zigbee Green Power Device |
| Network Size (theoretical # of nodes) | Up to 65,000 |
| Radio Technology | IEEE 802.15.4-2011 |
| Frequency Band / Channels | 2.4 GHz (ISM band) 16-channels (2 MHz wide) |
| Data Rate | 250 Kbits/sec |
| Communication Range (Average) | Up to 300+ meters (line of sight) Up to 75-100 meter indoor |
| Low Power Support | Sleeping End Devices Zigbee Green Power Devices (energy harvesting) |
| Logical device support | Each physical device may support up to 240 end-points (logical devices) |
- Device types
- Zigbee coordinator (ZC): The most capable device, the coordinator forms the root of the network tree and may bridge to other networks. There is precisely one Zigbee coordinator in each network since it is the device that started the network originally.
- Zigbee router (ZR): As well as running an application function, a router can act as an intermediate router, passing data on from other devices.
- Zigbee end device (ZED): Contains just enough functionality to talk to the parent node (either the coordinator or a router); it cannot relay data from other devices. This relationship allows the node to be asleep a significant amount of the time thereby giving long battery life. A ZED requires the least amount of memory and thus can be less expensive to manufacture than a ZR or ZC.
1.1.4 Z-Wave (z-wavealliance.org)
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Z-Wave Technology （智慧家庭物联网场景）
The Z-Wave protocol is an interoperable, wireless, RF-based communications technology designed specifically for control, monitoring and status reading applications in residential and light commercial environments. -
频率低于1GHz，干扰较小（不同国家的频点不同，怎么兼容？）
Operates in the sub-1GHz band; impervious to interference from Wi-Fi and other wireless technologies in the 2.4-GHz range (Bluetooth, ZigBee, etc.)
-
技术认证by Silicon Labs, 市场认证by Z-Wave Alliance.
1.2 长距无线技术
1.2.1 SigFox (“0G Network”)
- SigFox is a French global network operator for Internet of Things (IoT) founded in 2010. It claimed to opterate global 0G network to send and receive data without the need for complex connections or SIM cards. It is deployed in 72+ countries(包括港澳台，不含大陆) and regions, across all five continents. It currently covers 5.9 million km², and 1.3 billion people. 18+ million objects are connected to the 0G network, and 75+ million messages are sent every day.
- Sigfox employs the differential binary phase-shift keying (DBPSK) and the Gaussian frequency shift keying (GFSK) that enables communication using the Industrial, Scientific and Medical (ISM) radio band which uses 868 MHz in Europe and 902 MHz in the US. It utilizes a wide-reaching signal that passes freely through solid objects, called “Ultra Narrowband” and requires little energy, being termed a “low-power wide-area network” (LPWAN). The network is based on one-hop star topology and requires a mobile operator to carry the generated traffic.
1.2.2 LoRa (Semtech公司主导，用户量最大)
- LoRa（long range 的缩写）采用的扩频调制技术源于chirp spread spectrum (CSS) 技术。Semtech Corporation 的 LoRa 是一种长距离、低功耗无线平台，是事实上的物联网 (IoT) 无线平台。LoRa 网络已覆盖 100 多个国家/地区的数亿台器件，致力于打造一个更智慧的地球。
- LoRaWAN is a standard for interoperability managed by the LoRa Alliance (lora-alliance.org), a non-profit technology alliance of which Semtech is a founding member and board sponsor. While most IoT use cases can be solved by the vast LoRaWAN ecosystem, customers may consider LoRa PHY with a proprietary network implementation on top. With over 208 million end nodes deployed, there are use cases for LoRa in nearly every vertical market.
1.2.3 NB-IoT
- Narrowband Internet of things (NB-IoT) is a low-power wide-area network (LPWAN) radio technology standard developed by 3GPP for cellular devices and services. The specification was frozen in 3GPP Release 13 (LTE Advanced Pro), in June 2016. Other 3GPP IoT technologies include eMTC (enhanced Machine-Type Communication) and EC-GSM-IoT.
- NB-IoT focuses specifically on indoor coverage, low cost, long battery life, and high connection density. NB-IoT uses a subset of the LTE standard, but limits the bandwidth to a single narrow-band of 200kHz. It uses OFDM modulation for downlink communication and SC-FDMA for uplink communications. IoT applications which require more frequent communications will be better served by NB-IoT, which has no duty cycle limitations operating on the licensed spectrum.
- In March 2019, the Global Mobile Suppliers Association (GSA) announced that over 100 operators had either NB-IoT or LTE-M networks. This number had risen to 142 deployed/launched networks by September 2019.
1.2.4 eMTC
- LTE-M (LTE-MTC, Machine Type Communication), which includes eMTC (enhanced Machine Type Communication), is a type of low power wide area network (LPWAN) radio technology standard developed by 3GPP to enable a wide range of cellular devices and services (specifically, for machine-to-machine and Internet of Things applications). The specification for eMTC (LTE Cat-M1) was frozen in 3GPP Release 13 (LTE Advanced Pro), in June 2016.
- The advantage of LTE-M over NB-IoT is its comparatively higher data rate, mobility, and voice over the network, but it requires more bandwidth, is more costly, and cannot be put into guard band frequency band for now.
1.2.5 关于 LoRaWAN 和窄带物联网的 10 件事(https://blog.semtech.cn/title-10-things-about-lorawan-nb-iot)
- Ecosystem
LoRaWAN is supported by the LoRa Alliance®, an open, non-profit association of more than 500 members. Its members closely collaborate and share experiences to promote and drive the success of the LoRaWAN protocol as the leading open global standard for secure, carrier-grade IoT LPWAN connectivity.
NB-IoT 得到了第三代合作伙伴计划 (3GPP) 和 GSMA 的支持。这两个电信标准协会都以推广蜂窝网络和器件为目标。 - 频谱
LoRaWAN 针对超低功耗和长距离应用进行了优化。因此，网络在免授权的 ISM sub-1 GHz 频谱网络上运行，可供网络运营商和器件制造商免费访问。
NB-IoT使用蜂窝频谱网络，主要针对频谱效率进行了优化；使用频段的许可费用非常高，只有少数有能力负担费用的被许可方可以使用。 - 部署状态
根据 LoRa Alliance 的数据，当今 49 个国家/地区的 83 个公共网络运营商正在使用 LoRaWAN，并有更多的私有企业网络在 LoRaWAN 上运行。
代表NB-IoT、LTE 和其他移动网络利益的组织 GSMA 预计 40 个国家/地区即将推出窄带物联网网络。 - 部署选项
LoRaWAN 网络实现了高度灵活的部署。它们可安装在室内或室外的公共、私有或混合网络中。LoRaWAN 信号能够深入穿透城市设施；在农村开阔环境中，每个网关可覆盖 30 英里。
NB-IoT利用 LTE 蜂窝基础设施。因此这些是采用 4G/LTE 蜂窝信号塔的室外公共网络。即使传感器超出基站范围，也无法轻易将基站部署在其他地方。 - 协议
LoRaWAN 协议允许异步发送数据，仅在必要时发送数据。这样可以将现场传感器设备的电池寿命延长多达 10 年，从而降低了电池更换成本。
NB-IoT保持与蜂窝网络的同步连接，无论是否存在要发送的数据。这会大大降低传感器设备的电池寿命，导致高昂的电池更换成本，造成许多应用中花费过高。 - 发射电流
LoRaWAN 提供 10 dBm 时 18 mA、20 dBm 时 84 mA 的发射电流。调制方面的差异使得 LoRaWAN 可由成本极低的电池（包括纽扣电池）供电。
NB-IoT传感器在 23 dBm 时约消耗 220 mA、在 13 dBm 时消耗 100 mA，因此它需要更多的功率才能工作，且需要更频繁地更换电池或使用容量更大的电池。 - 接收电流
LoRaWAN 为远程传感器降低传感器 BOM 成本、延长电池寿命。约 5 mA 的接收电流意味着 LoRaWAN 的整体功耗降低了 3-5 倍。
NB-IoT的接收电流约为 40 mA。蜂窝网络和器件之间的通信平均消耗超过 110 mA，一次持续数十秒。对于需要运行 3 年、5 年或 10 年以上的器件，协议开销对电池寿命有重大影响。 - 数据传输速率
LoRaWAN 的数据速率约为 293 bps-50 kbps。LoRaWAN 协议根据传感器与网关的距离来动态调整数据速率，从而优化信号传输时间并减少冲突。
NB-IoT的峰值数据速率约为 250 kbps，更适合功率预算和数据速率更高（高于 50 kbps）的用例。 - 链路预算
LoRaWAN 的 MCL 信号根据地区法规限制而不同。在最好的情形下，链路预算介于 155 dB 至 170 dB 之间。
NB-IoT需要以低比特率对远程传感器频繁重复传输，才能支持远程传感器。在最好的情形下，链路预算为 164 dB。 - 移动性
LoRaWAN 可支持移动传感器并在资产从一个位置移动到另一位置时对其进行追踪。对于许多应用来说，即使没有 GPS，也可达到足够的精度。
如今，NB-IoT仅限于空闲模式小区重选，未对移动资产追踪进行充分的优化。
1.3 NB-IoT
1.3.1 NB-IoT解决方案总体架构
- 终端：能连2345G基站？软SIM？传感器接口什么样？UU接口沿用4G网络所用的说法，指UE和UTRAN接口，就是空中接口。CoAP(Constrained Application Protocol)
- 频段：电信800MHz, 联通和移动900MHz
1.3.2 NB-IoT关键特性
- 低功耗
- PSM (Power Saving Mode)
- eDRX (Extended Discontinuous Reception)
- 低成本
- 180KHz窄带宽，基带复杂度低
- 低采样率，缓存要求小
- 单天线、半双工，RF成本低
- 峰均比低，功放效率高
- 协议栈简化（500KByte)，减少片内存储。
- 强覆盖：比GSM/LTE增益高20dB
- NB-IoT比GPRS增加20 dB MCL (Maximum Coupling Loss), 所以覆盖距离是其3倍，或者多穿透2堵墙
- 深覆盖解决方案将180KHz功率谱压缩到15KHz，密度提升，增加11dB增益。
- 重复发送提升下行9dB、上行12dB增益。
- 与LoRa\Sigfox对比
华为对运营商的说法。不过其他制式可能不满足数据安全要求？
1.4 Other Views
- Killed off by NTT DoCoMo: NB-IoT still kicking globally, but for how long?(https://www.iot-now.com/2020/05/11/102743-killed-off-by-ntt-docomo-nb-iot-still-kicking-globally-but-for-how-long/)
(1) Fragmentation in the LPWA market.
(2) High volumes of connected things haven’t arrived.
(3) NB-Iot implementations in different networks do not interwork.
(4) Prcing is not low enough.
(5) Europe will drop NB-IoT. North America is more likely to adopt LTE-based solutions than NB-IoT.