4. Accounts receivables, net and other receivables

Accounts receivable, net of allowances for doubtful accounts and other receivables consisted of the following:

	December 31,
	2017		2016
Trade receivables, net of allowances	$	25,079	$	39,404
Unbilled access fees		274		21
Unbilled platform service arrangements		795		3,553

Accounts receivable, net	$	26,148	$	42,978


Unbilled access fees	$	817	$	867
Unbilled platform service arrangements		3		694

Non-current other receivables	$	820	$	1,561

Access fees are recorded under long-term contracts with our wholesale partners that are telecom operators for access to our DAS at our managed and operated locations. Platform service fees are recorded under long-term contracts with our wholesale Wi-Fi partners. These access and platform service fees escalate on an annual basis from which we receive fixed contractual payments and recognize revenue ratably over the term of the contracts.

Included in accounts receivables, net for the periods indicated was the allowance for doubtful accounts, which consisted of the following:

	Allowance for Doubtful Accounts
Balance, December 31, 2014	$	394
Additions charged to operations		304
Deductions from reserves, net		(93	)

Balance, December 31, 2015		605
Additions charged to operations		116
Deductions from reserves, net		(279	)

Balance, December 31, 2016		442
Additions charged to operations		773
Deductions from reserves, net		(352	)

Balance, December 31, 2017	$	863