Note 4. Balance Sheet Components

Property and Equipment, Net

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

	As of January 31, 2016			As of April 30, 2016
Test equipment	$	65,663		$	83,384
Computer, equipment and software		31,388			40,442
Furniture and fixtures		2,852			3,532
Leasehold improvements		4,935			6,055
Total property and equipment		104,838			133,413
Less: accumulated depreciation and amortization		(52,209	)		(62,158	)
Property and equipment, net	$	52,629		$	71,255

Depreciation and amortization expense was $6.2 million and $10.1 million for the three months ended April 30, 2015 and 2016, respectively.

Intangible Assets, Net

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

	As of January 31, 2016			As of April 30, 2016
Technology patents	$	9,125		$	9,125
Accumulated amortization		(2,145	)		(2,471	)
Intangible assets, net	$	6,980		$	6,654

Intangible assets amortization expense was $326,000 for the three months ended April 30, 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 April 30, 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	$	978
2018		1,304
2019		1,304
2020		1,304
2021		1,304
Thereafter		460
Total	$	6,654

Accrued Expenses and Other Liabilities

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

	As of January 31, 2016		As of April 30, 2016
Sales and use tax payable	$	299	$	151
Accrued professional fees		3,044		2,777
Accrued marketing		2,684		3,804
Accrued travel and entertainment expenses		2,182		2,458
Income tax payable		1,791		1,292
Other accrued liabilities		4,076		5,488
Total accrued expenses and other liabilities	$	14,076	$	15,970