The following is a description of the principal activities from which we generate our revenue by reportable segment.

Network Solutions includes hardware products and software-defined next-generation virtualized solutions used in service provider or business networks, as well as prior generation products. The majority of the revenue from this segment is from hardware sales. In certain transactions, we are also the lessor in sales-type lease arrangements for network equipment. These arrangements typically include network equipment, network implementation services and maintenance services. Network implementation services and maintenance services are included in the Services & Support segment discussed below. See Note 11 for additional information.

To complement our Network Solutions segment, we offer a complete portfolio of maintenance, network implementation and solutions integration and managed services, which include hosted cloud services and subscription services.

In addition to our reporting segments, we also report revenue in the following three categories – Access & Aggregation, Subscriber Solutions & Experience, and Traditional & Other Products.

The following table disaggregates our revenue by reportable segment and revenue category for the three months ended June 30, 2019 and 2018:

	For the Three Months Ended
	June 30, 2019						June 30, 2018
(In thousands)	Network Solutions		Services & Support		Total		Network Solutions		Services & Support		Total
Access & Aggregation	$	96,262	$	13,159	$	109,421	$	75,222	$	9,520	$	84,742
Subscriber Solutions & Experience⁽¹⁾		38,444		2,058		40,502		33,306		1,254		34,560
Traditional & Other Products		4,461		2,007		6,468		6,535		2,211		8,746
Total	$	139,167	$	17,224	$	156,391	$	115,063	$	12,985	$	128,048

The following table disaggregates our revenue by reportable segment and revenue category for the six months ended June 30, 2019 and 2018:

	For the Six Months Ended
	June 30, 2019						June 30, 2018
(In thousands)	Network Solutions		Services & Support		Total		Network Solutions		Services & Support		Total
Access & Aggregation	$	181,935	$	27,264	$	209,199	$	144,607	$	21,815	$	166,422
Subscriber Solutions & Experience⁽¹⁾		73,163		4,092		77,255		62,083		2,578		64,661
Traditional & Other Products		9,891		3,837		13,728		13,626		4,145		17,771
Total	$	264,989	$	35,193	$	300,182	$	220,316	$	28,538	$	248,854

Revenue is measured based on the consideration we expect to receive in exchange for transferring goods or providing services to a customer and as performance obligations under the terms of the contract are satisfied. For transactions where there are multiple performance obligations, we account for individual products and services separately if they are distinct (if a product or service is separately identifiable from other items and if a customer can benefit from it on its own or with other resources that are readily available to the customer). As of June 30, 2019, we did not have any significant performance obligations related to customer contracts that had an original expected duration of one year or more, other than maintenance services, which are satisfied over time.

The following table provides information about receivables, contract assets and unearned revenue from contracts with customers:

(In thousands)	June 30, 2019		December 31, 2018
Accounts receivable, net	$	116,661	$	99,385
Contract assets⁽¹⁾	$	2,251	$	3,766
Unearned revenue	$	12,910	$	17,940
Non-current unearned revenue	$	4,265	$	5,296

Of the outstanding unearned revenue balance at December 31, 2018, $3.6 million and $10.5 million was recognized as revenue during the three and six months ended June 30, 2019, respectively.