Operating Segment - Product Category (Details)	3 Months Ended								12 Months Ended
	Mar. 27, 2016 USD ($)	Dec. 27, 2015 USD ($)	Sep. 27, 2015 USD ($)	Jun. 28, 2015 USD ($)	Mar. 29, 2015 USD ($)	Dec. 28, 2014 USD ($)	Sep. 28, 2014 USD ($)	Jun. 29, 2014 USD ($)	Mar. 27, 2016 USD ($) product	Mar. 29, 2015 USD ($)	Mar. 30, 2014 USD ($)
Revenue and Gross Profit from External Customers
Number of product categories | product									4
Revenues	$ 114,154,100	$ 139,510,700	$ 142,353,300	$ 134,664,000	$ 112,962,200	$ 135,188,700	$ 148,521,800	$ 152,946,300	$ 530,682,100	$ 549,619,000	$ 560,086,600
Gross Profit	$ 23,018,900	$ 29,453,400	$ 30,511,700	$ 28,981,900	$ 24,311,800	$ 28,820,900	$ 32,361,000	$ 32,144,800	111,965,900	117,638,500	126,357,900
Base station infrastructure
Revenue and Gross Profit from External Customers
Revenues									206,604,000	224,135,000	252,983,000
Gross Profit									51,610,000	55,732,000	64,318,000
Network systems
Revenue and Gross Profit from External Customers
Revenues									83,480,000	96,399,000	89,411,000
Gross Profit									12,893,000	13,549,000	13,988,000
Installation, test and maintenance
Revenue and Gross Profit from External Customers
Revenues									34,936,000	41,790,000	45,343,000
Gross Profit									6,607,000	8,351,000	9,306,000
Mobile device accessories
Revenue and Gross Profit from External Customers
Revenues									205,662,000	187,295,000	172,350,000
Gross Profit									$ 40,856,000	$ 40,007,000	$ 38,746,000