GOODWILL AND OTHER IDENTIFIABLE INTANGIBLE ASSETS, NET

Identifiable Intangible Assets, Net

Amortizable identifiable intangible assets, net as of September 30, 2019 and 2018 were comprised of the following (in thousands):



	September 30, 2019							September 30, 2018
	Gross carrying amount		Accum. amort.			Net		Gross carrying amount		Accum. amort.			Net
Purchased and core technology	$	57,699	$	(50,986	)	$	6,713	$	58,102	$	(48,693	)	$	9,409
License agreements	102		(74		)	28		102		(46		)	56
Patents and trademarks	14,577		(11,970		)	2,607		15,701		(12,242		)	3,459
Customer relationships	46,315		(25,266		)	21,049		46,605		(21,049		)	25,556
Non-compete agreements	600		(330		)	270		600		(210		)	390
Order backlog	1,800		(1,800		)	—		1,800		(1,350		)	450
Total	$	121,093	$	(90,426	)	$	30,667	$	122,910	$	(83,590	)	$	39,320

Amortization expense is included in our Consolidated Statements of Operations in cost of sales and general and administrative expense. Amortization expense in cost of sales includes amortization for purchased and core technology and certain patents and trademarks.

Amortization expense for fiscal years 2019, 2018 and 2017 was as follows (in thousands):



Fiscal year	Total
2019	$	8,818
2018	$	9,435
2017	$	2,597

3. GOODWILL AND OTHER IDENTIFIABLE INTANGIBLE ASSETS, NET (CONTINUED)

Estimated amortization expense for the next five years is as follows (in thousands):



Fiscal year	Total
2020	$	8,277
2021	$	7,434
2022	$	6,590
2023	$	4,392
2024	$	3,689

Goodwill

The changes in the carrying amount of goodwill by reportable segments are (in thousands):



	Fiscal years ended September 30,
	IoT Products and Services			IoT Solutions			Total
Balance on September 30, 2017	$	98,981		$	33,014		$	131,995
Acquisitions	5,663			17,553			23,216
Foreign currency translation adjustment	(286		)	(390		)	(676		)
Balance on September 30, 2018	$	104,358		$	50,177		$	154,535
Foreign currency translation adjustment	(839		)	(274		)	(1,113		)
Balance at September 30, 2019	$	103,519		$	49,903		$	153,422

No goodwill impairment has been recorded in any period presented.