Table 1:

Tree characteristics and signal parameters (in dB) measured in a municipal Wi-Fi network in Mountain View, California.

Location	Tree sp.	Leaf size (mm × mm)	# of trees in LOS	Canopy depth (m)	Dist. to AP (m)	Δ Signal^{^z}, summer Clear - Tree in leaf	Δ Signal, winter Clear - Tree defoliated	Δ Noise, summer Clear - Tree in leaf	Δ Noise, winter Clear - Tree defoliated
Bernardo Street	Platanus × acerifolia	100 × 100 to 160 × 180	11	24.5	150	−0.3	3.5	0.2	0
			6	14	90	−1	3.2	0.3	0.1
			3	6.5	30	1.9	3.2	−0.1	0.7
Bernardo Street	Prunus cerasifera	40 × 80	4	23	90	7.4	8.7	−0.3	−0.7
Cuesta Park	Liriodendron tulipifera	120 × 120	1	3	30	13.1	11	0	−1
Cuesta Park	Liriodendron tulipifera	120 × 120	1	3	10	11.8	2.7	0.4	−1.7
Villa Street	Pistacia chinensis	70 × 20 (240 × 170)	4	41	54	--	--	--	--
Villa Street	Pistacia chinensis	70 × 20 (240 × 170)	3	22	23	3.6	4.2	0.9	0.8
Glenborough Street	Liquidambar styraciflua	100 × 120	9	52	100	7.6	3.9	0	−0.7
			4	21	60	2.2	5.1	−0.4	−0.1
			1	5	30	2.6	2.3	0.1	0.1
Cuesta Park	Pinus radiata, Sequoia sempervirens	100 × 1.5, 18 × 40 (150 × 20)	7	75	90	18.7	14	−0.1	1.1
			3	35	45	5.1	5.6	−1.2	−0.3
			1	10	20	2.1	2.2	−0.5	1.2
Cuesta Park	Pinus pinea	140 × 1.5	2	25	60	4	9.4	0.3	−0.1
Average attenuation:				(all trees: n = 7):		5.3^{^y}	5.6^{^y}	−0.03^{^x}	−0.04
(defoliated broadleaf: n = 5):							4.8^{^y}		−0.20

↵^zNegative values indicate a stronger signal (or lower noise) with tree(s) in LOS.
↵^ySignificant differences (P < 0.05) in signal level between clear & tree condition.
↵^xDifferences of < 0.5 dB cannot be measured reliably in the outdoor environment.