Business Segments, Revenue Information by Product (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Revenue and Gross Profit from External Customer [Line Items]
Revenue from external customers	$ 148,521,800	$ 146,526,000	$ 301,468,100	$ 290,634,800
Gross profit	35,436,000	36,492,800	70,684,800	71,930,700
Base Station Infrastructure [Member]
Revenue and Gross Profit from External Customer [Line Items]
Revenue from external customers	64,129,000	67,888,000	127,016,000	137,429,000
Gross profit	16,817,000	18,765,000	33,892,000	37,654,000
Network Systems [Member]
Revenue and Gross Profit from External Customer [Line Items]
Revenue from external customers	27,496,000	21,838,000	58,040,000	40,901,000
Gross profit	4,174,000	3,745,000	8,859,000	7,563,000
Installation, Test and Maintenance [Member]
Revenue and Gross Profit from External Customer [Line Items]
Revenue from external customers	10,663,000	12,588,000	21,585,000	22,350,000
Gross profit	2,284,000	2,780,000	4,817,000	5,130,000
Mobile Device Accessories [Member]
Revenue and Gross Profit from External Customer [Line Items]
Revenue from external customers	46,234,000	44,212,000	94,827,000	89,955,000
Gross profit	$ 12,161,000	$ 11,203,000	$ 23,117,000	$ 21,584,000