Employee Benefit Plans and Stock-based Compensation (Tables)

6 Months Ended

Jul. 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 six months endedJuly 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	2,000		—		—		—		—
Granted	(2,890	)	886		3.15		1,336		3.14
Options exercised	—		(1	)	2.25		—		—
Shares released	—		—		—		(1,054	)	6.72
Forfeited or cancelled	1,754		(1,375	)	6.43		(253	)	5.89
Balance at July 1, 2016	7,014		5,184		$	6.02	2,211		$	4.74

Summary of Stock Options Outstanding

The following table summarizes information about stock options outstanding as of July 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	4,882	$	6.07	4.1	$	98
Exercisable	3,057	6.54		3.0	98

Summary of Restricted Stock Units Outstanding

The following table summarizes information about RSUs outstanding as of July 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	1,959	0.9	$	5,897

Schedule of Defined Benefit Plans Obligations

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

	July 1, 2016
Projected benefit obligation:
Acquired from TVN acquisition	$	5,907
Service cost	94
Interest cost	39
Foreign currency translation adjustment	27
As of July 1, 2016	$	6,067
Presented on the Condensed Consolidated Balance Sheets under:
Current portion (presented under “Accrued liabilities”)	$	243
Long-term portion (presented under “Other non-current liabilities”)	$	5,824

Schedule of Assumptions Used - Employee Benefit Plans Obligation

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

	July 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 six months)	$	47
2017	117
2018	227
2019	366
2020	433
2021 - 2025	2,311
	$	3,501

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				Six months ended
	July 1, 2016		July 3, 2015		July 1, 2016		July 3, 2015
Stock-based compensation in:
Cost of revenue	$	424	$	422	$	651	$	950
Research and development expense	841		1,027		1,810		2,175
Selling, general and administrative expense	1,503		2,435		3,401		4,893
Total stock-based compensation in operating expense	2,344		3,462		5,211		7,068
Total stock-based compensation	$	2,768	$	3,884	$	5,862	$	8,018

Valuation Assumptions for Stock Options

	Employee Stock Options
	Three months ended				Six months ended
	July 1, 2016		July 3, 2015		July 1, 2016		July 3, 2015
Expected term (years)	4.30		4.60		4.30		4.70
Volatility	36	%	37	%	36	%	38	%
Risk-free interest rate	1.1	%	1.5	%	1.4	%	1.5	%
Expected dividends	0.0	%	0.0	%	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		0.50
Volatility	54	%	35	%
Risk-free interest rate	0.4	%	0.1	%
Expected dividends	0.0	%	0.0	%
Estimated weighted average fair value per share at purchase date	$1.19		$1.75