Facebook Project ARIES Uses Massive MIMO to Radically Improve Specrum Efficiency

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.

Project ARIES, presently in test mode, features a base station with 96 antennas, supporting 24 simultaneous streams.

Facebook 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

source: Wikipedia