Balance Sheet Components

Property and Equipment, Net

Property and equipment, net, consists of the following (in thousands):



	As of January 31, 2016			As of July 31, 2016
Test equipment	$	65,663		$	94,914
Computer, equipment and software	31,388			45,340
Furniture and fixtures	2,852			4,028
Leasehold improvements	4,935			7,839
Total property and equipment	104,838			152,121
Less: accumulated depreciation and amortization	(52,209		)	(73,598		)
Property and equipment, net	$	52,629		$	78,523

Depreciation and amortization expense was $7.2 million and $11.6 million for the three months ended July 31, 2015 and 2016 and $13.4 million and $21.7 million for the six months ended July 31, 2015 and 2016, respectively.

Intangible Assets, Net

Intangible assets, net, consist of the following (in thousands):



	As of January 31, 2016			As of July 31, 2016
Technology patents	$	9,125		$	10,125
Accumulated amortization	(2,145		)	(2,813		)
Intangible assets, net	$	6,980		$	7,312

During the three months ended July 31, 2016, we acquired a portfolio of technology patents for $1.0 million with an estimated weighted average useful life of 5 years. Intangible assets amortization expense was $326,000 and $342,000 for the three months ended July 31, 2015 and 2016 and $652,000 and $668,000 for the six months ended July 31, 2015 and 2016. Due to the defensive nature of these patents, the amortization is included in general and administrative expenses in the condensed consolidated statements of operations.

As of July 31, 2016, expected amortization expense for intangible assets for each of the next five years and thereafter is as follows (in thousands):



Fiscal Years Ending January 31,	Estimated Future Amortization Expense
Remainder of 2017	$	752
2018	1,504
2019	1,504
2020	1,504
2021	1,504
Thereafter	544
Total	$	7,312

Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities consist of the following (in thousands):



	As of January 31, 2016		As of July 31, 2016
Sales and use tax payable	$	299	$	150
Accrued professional fees	3,044		3,214
Accrued marketing	2,684		6,237
Accrued travel and entertainment expenses	2,182		3,223
Income tax payable	1,791		1,285
Other accrued liabilities	4,076		6,355
Total accrued expenses and other liabilities	$	14,076	$	20,464