REVENUE

Revenue Disaggregation

The following summarizes our revenue by geographic location of our customers:



	Fiscal years ended September 30,
($ in thousands)	2019		2018 (as adjusted)*		2017 (as adjusted)*
North America, primarily the United States	$	184,022	$	161,924	$	117,455
Europe, Middle East & Africa	39,896		39,211		39,403
Rest of world	30,285		25,758		24,482
Total revenue	$	254,203	$	226,893	$	181,340

*Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which we adopted on October 1, 2018.

11. REVENUE (CONTINUED)

The following summarizes our revenue by the timing of revenue recognition:



	Fiscal years ended September 30,
($ in thousands)	2019		2018 (as adjusted)*		2017 (as adjusted)*
Transferred at a point in time	$	231,387	$	212,448	$	176,567
Transferred over time	22,816		14,445		4,773
Total revenue	$	254,203	$	226,893	$	181,340

*Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which we adopted on October 1, 2018.

Contract Balances

Contract Assets

Contract assets consist of subscriber assets. These subscriber assets relate to fees in certain contracts that we charge our customers so they can begin using equipment. In these cases, we retain the ownership of the equipment that the customer uses. The total net book value of subscriber assets was $2.1 million at both September 30, 2019 and September 30, 2018 and is included in property, equipment and improvements, net. Depreciation expense for these subscriber assets was $1.1 million, $0.5 million and $0.1 million for fiscal 2019, 2018 and 2017, respectively. We depreciate the cost of this equipment over its useful life (typically three years).

Contract Liabilities

The timing of revenue recognition may differ from the timing of invoicing to customers. Customers are invoiced for subscription services in advance on a monthly, quarterly or annual basis. Contract liabilities consist of unearned revenue related to annual or multi-year contracts for subscription services and related implementation fees for our IoT Solutions segment and our Digi Remote Manager^® services in our IoT Products & Services segment.

Changes in unearned revenue were:



	Fiscal year ended September 30,
($ in thousands)	2019
Unearned revenue, beginning of period*	$	3,933
Billings	43,071
Revenue recognized	(41,979		)
Unearned revenue, end of period	$	5,025

*Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which we adopted on October 1, 2018.

Remaining Transaction Price

Transaction price allocated to the remaining performance obligations represents contracted revenue that has not been recognized, which includes unearned revenue and unbilled amounts that will be recognized as revenue in future periods. As of September 30, 2019 approximately $14.9 million of revenue is expected to be recognized from remaining performance obligations for subscriptions contracts. We expect to recognize revenue on approximately $6.8 million of remaining performance obligations over the next twelve months. Revenue from the remaining performance obligations we expect to recognize over a range of two to five years.