In addition to pioneering a new fixed wireless access system for Internet access, Facebook also is working on a new spectrally-efficient air interface based on use of massive MIMO antenna arrays.
Terragraph is Facebook’s proposed new 60-GHz fixed wireless system focused on bringing high-speed internet connectivity to dense urban areas.
Project ARIES, presently in test mode, complements Terragraph by boosting spectrum efficiency. Project ARIES features a base station with 96 antennas, supporting 24 simultaneous streams. The first version of the prototype antenna array uses 96 transmit antennas, providing 10 times the spectral efficiency.
Facebook Project ARIES so far has achieved 71 bps/Hz, and Facebook engineers are aiming for supplying 100 bps/Hz eventually.
By way of comparison, that would surpass the efficiency of Long Term Evolution and vastly outperform most other interfaces ever commercially deployed.
In large part, that effort is based on use of massive MIMO.
| Service | Standard | Max. net bitrateR
per carrier per one spatial stream (Mbit/s) |
BandwidthB
per carrier (MHz) |
System spectral efficiency (R/B)/K
((bit/s)/Hz per site) |
| 1G cellular | NMT 450 modem | 0.0012 | 0.025 | 0.064 |
| 1G cellular | AMPS modem | 0.0003[2] | 0.030 | 0.0015 |
| 2G cellular | GSM | 0.013 × 8 timeslots = 0.104 | 0.2 | 0.17[4] (in 1999) |
| 2G cellular | D-AMPS | 0.013 × 3 timeslots = 0.039 | 0.030 | 0.45[4] (in 1999) |
| 2.75Gcellular | CDMA2000 1× voice | 0.0096 per phone call × 22 calls | 1.2288 | 0.172 (fully loaded) |
| 2.75Gcellular | GSM + EDGE | 0.384 (typ. 0.20) | 0.2 | 0.33[4] |
| 2.75Gcellular | IS-136HS + EDGE | 0.384 (typ. 0.27) | 0.200 | 0.45[4] |
| 3G cellular | WCDMA FDD | 0.384 | 5 | 0.51 |
| 3G cellular | CDMA2000 1x PD | 0.153 | 1.2288 | 0.1720 (fully loaded) |
| 3G cellular | CDMA2000 1×EV-DO Rev.A | 3.072 | 1.2288 | 1.3 |
| FixedWiMAX | IEEE 802.16d | 96 | 20 | 1.2 |
| 3.5G cellular | HSDPA | 21.1 | 5 | 4.22 |
| 4G MBWA | iBurst HC-SDMA | 3.9 | 0.625 | 7.23 |
| 4G cellular | LTE | 81.6 | 20 | 16.32 |
| 4G cellular | LTE-Advanced | 75 | 20 | 30 |
| Wi-Fi | IEEE 802.11a/g | 54 | 20 | 0.900 |
| Wi-Fi | IEEE 802.11n | 72.2 (short GI) | 20 | 1.2 |
| Wi-Fi | IEEE 802.11ac | 433.3 (short GI) | 80 | |
| WiGig | IEEE 802.11ad | 6756 | 2160 | 1 |
| TETRA | ETSI | 4 timeslots = 0.036 | 0.025 | |
| Digital radio | DAB | 0.576 to 1.152 | 1.712 | 0.08 to 0.17 |
| Digital radio | DAB with SFN | 0.576 to 1.152 | 1.712 | 0.34 to 0.67 |
| Digital TV | DVB-T | 31.67 (typ. 22.0) | 8 | 0.55 |
| Digital TV | DVB-T with SFN | 31.67 (typ. 22.0) | 8 | 4.0 (typ. 2.8) |
| Digital TV | DVB-H | 5.5 to 11 | 8 | 0.14 to 0.28 |
| Digital TV | DVB-H with SFN | 5.5 to 11 | 8 | 0.68 to 1.4 |
| Digital cable TV | DVB-C 256-QAMmode | 38 | 6 | N/A |
| Broadband modem | ADSL2 downlink | 12 | 0.962 | N/A |
| Broadband modem | ADSL2+ downlink | 28 | 2.109 | N/A |
| Telephone modem | V.92 downlink | 0.056 | 0.004 | N/A |
