Employee Benefit Plans and Stock-based Compensation (Tables)

3 Months Ended

Apr. 01, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Company's Stock Option and Restricted Stock Unit Activity

The following table summarizes the Company’s stock option and RSU activities during the three months endedApril 1, 2016 (in thousands, except per share amounts):

			Stock Options Outstanding				Restricted Stock Units Outstanding
	Shares Available for Grant		Number of Shares		Weighted Average Exercise Price		Number of Units		Weighted Average Grant Date Fair Value
Balance at December 31, 2015	6,150		5,674		$	6.56	2,182		$	6.99
Authorized	—		—		—		—		—
Granted	(2,802	)	876		3.14		1,284		3.15
Options exercised	—		(1	)	2.25		—		—
Shares released	—		—		—		(977	)	6.72
Forfeited or cancelled	980		(679	)	6.38		(201	)	5.89
Balance at April 1, 2016	4,328		5,870		$	6.08	2,288		$	4.88

Summary of Stock Options Outstanding

The following table summarizes information about stock options outstanding as of April 1, 2016 (in thousands, except per share amounts):

	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Vested and expected to vest	5,491	$	6.13	4.0	$	240
Exercisable	3,479	6.51		2.8	133

Summary of Restricted Stock Units Outstanding

The following table summarizes information about RSUs outstanding as of April 1, 2016 (in thousands, except per share amounts):

	Number of Shares Underlying Restricted Stock Units	Weighted Average Remaining Vesting Period (Years)	Aggregate Fair Value
Vested and expected to vest	1,971	1.1	$	6,484

Schedule of Defined Benefit Plans Obligations

hanges to the Company’s defined benefit pension plan obligations are shown below (in thousands):

Projected benefit obligation:
Acquired from TVN acquisition	$	5,907
Service cost	23
Interest cost	10
Foreign currency translation adjustment	149
As of April 1, 2016	6,089
Presented on the Condensed Consolidated Balance Sheets under:
Current portion (presented under “Accrued liabilities”)	187
Long-term portion (presented under “Other non-current liabilities”)	$	5,902

Schedule of Assumptions Used - Employee Benefit Plans Obligation

The following assumptions were used in determining the Company’s pension obligation:

	April 1, 2016
Discount rate	2.0	%
Mobility rate	2.2	%
Salary progression rate	2.0	%

Schedule of Expected Benefit Payments

Future benefits expected to be paid in each of the next five years, and in the aggregate for the five year period thereafter are as follows (in thousands):

Years ending December 31,
2016 (remaining nine months)	$	96
2017	120
2018	232
2019	373
2020	442
2021 - 2025	2,357
	$	3,620

Summary of Stock-Based Compensation Expense

Stock-based Compensation

The following table summarizes stock-based compensation expense for all plans (in thousands):

	Three months ended
	April 1, 2016		April 3, 2015
Stock-based compensation in:
Cost of revenue	$	227	$	528
Research and development expense	969		1,148
Selling, general and administrative expense	1,898		2,458
Total stock-based compensation in operating expense	2,867		3,606
Total stock-based compensation	$	3,094	$	4,134

Valuation Assumptions for Stock Options

	Employee Stock Options
	Three months ended
	April 1, 2016		April 3, 2015
Expected term (years)	4.30		4.70
Volatility	36	%	38	%
Risk-free interest rate	1.4	%	1.6	%
Expected dividends	0.0	%	0.0	%

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions

	ESPP Purchase Period Ending
	June 30, 2016		June 30, 2015
Expected term (years)	0.50		0.49
Volatility	52	%	35	%
Risk-free interest rate	0.5	%	0.1	%
Expected dividends	0.0	%	0.0	%
Estimated weighted average fair value per share at purchase date	$1.17		$1.74