Bluetooth Low Energy (BLE)

Giriş
Bu teknoloji klasik Bluetooth çok güç tükettiği için çıkarıldı. Hızı 100kbps menzili ise en fazla 150 metre civarında. Bunu 100 metre kabul etmek daha doğru. 77 metrede 10mW güç tüketiyor. Özellikleri şöyle.

Bluetooth Standard: Bluetooth 4.2 core specification Frequency: 2.4GHz (ISM) Range: 50-150m (Smart/BLE) Data Rates: 1Mbps (Smart/BLE)

Zigbee Standard: ZigBee 3.0 based on IEEE802.15.4 Frequency: 2.4GHz Range: 10-100m Data Rates: 250kbps

Z-Wave Standard: Z-Wave Alliance ZAD12837 / ITU-T G.9959 Frequency: 900MHz (ISM) Range: 30m Data Rates: 9.6/40/100kbit/s

6LowPAN Standard: RFC6282 Frequency: (adapted and used over a variety of other networking media including Bluetooth Smart (2.4GHz) or ZigBee or low-power RF (sub-1GHz) Range: N/A Data Rates: N/A

Thread Standard: Thread, based on IEEE802.15.4 and 6LowPAN Frequency: 2.4GHz (ISM) Range: N/A Data Rates: N/A

WiFi Standard: Based on 802.11n (most common usage in homes today) Frequencies: 2.4GHz and 5GHz bands Range: Approximately 50m Data Rates: 600 Mbps maximum, but 150-200Mbps is more typical, depending on channel frequency used and number of antennas (latest 802.11-ac standard should offer 500Mbps to 1Gbps)

Cellular Standard: GSM/GPRS/EDGE (2G), UMTS/HSPA (3G), LTE (4G) Frequencies: 900/1800/1900/2100MHz Range: 35km max for GSM; 200km max for HSPA Data Rates (typical download): 35-170kps (GPRS), 120-384kbps (EDGE), 384Kbps-2Mbps (UMTS), 600kbps-10Mbps (HSPA), 3-10Mbps (LTE)

NFC Standard: ISO/IEC 18000-3 Frequency: 13.56MHz (ISM) Range: 10cm Data Rates: 100–420kbps

Sigfox Standard: Sigfox Frequency: 900MHz Range: 30-50km (rural environments), 3-10km (urban environments) Data Rates: 10-1000bps

Neul Standard: Neul Frequency: 900MHz (ISM), 458MHz (UK), 470-790MHz (White Space) Range: 10km Data Rates: Few bps up to 100kbps

LoRaWAN Standard: LoRaWAN Frequency: Various Range: 2-5km (urban environment), 15km (suburban environment) Data Rates: 0.3-50 kbps.

BLE ilginç bir şekilde Stop-and-wait ARQ kullanıyor.

Topology
Broadcast, Point to Point ve Mesh olabilir.

Ana Kullanım Alanı
Açıklaması şöyle.

Use-cases that need continious streamaing of data, such as headphones, fitness band, wireless speakers, interactive displays, AssetTracking

Bağlanabilen Cihaz Sayısı
Açıklaması şöyle.

Bluetooth was originally designed for ‘personal area networks,’  with the original standard supporting 7 concurrent devices. And now we have Bluetooth low energy (BLE), which has a theoretically infinite limit.

Az Güç Tüketimi İçin Yapılanlar
Açıklaması şöyle.

They looked heavily at the amount of energy required to support communication. They considered every facet of "low energy," not just the radio — they looked at data format, packet size, how long the radio needed to be on to transmit those packets, how much memory was required to support it, what the power cost was for that memory, and what the protocol expects of the CPU, all while keeping overall BOM costs in mind. For example, they figured out that the radio should only be on for 1.5ms at a time. That’s a sweet spot — if you transmit for longer, the components heat up and thus require more power. They also figured out that button cell batteries are better at delivering power in short bursts as opposed to continuously. Further, they optimized it to be really durable against Wi-Fi interference because the protocols share the same radio space (2.4GHz).

Internet Protocol Support Profile (IPSP)
IPv6 paketlerinin BLE ile gönderilebilmesi (tunnel/tünel) içindir. Açıklaması şöyle

The Internet Protocol Support Profile (IPSP) allows devices to discover and communicate to other devices that support IPSP. The communication between the devices that support IPSP is done using IPv6 packets over the Bluetooth Low Energy transport. — Bluetooth 4.2 Specification