REVENUE

Revenue Disaggregation

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



	Three months ended December 31,
($ in thousands)	2019		2018
North America, primarily the United States	$	47,536	$	46,335
Europe, Middle East & Africa	8,516		10,104
Rest of world	6,265		5,874
Total revenue	$	62,317	$	62,313

9. REVENUE (CONTINUED)

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



	Three months ended December 31,
($ in thousands)	2019		2018
Transferred at a point in time	$	56,300	$	57,463
Transferred over time	6,017		4,850
Total revenue	$	62,317	$	62,313

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 of $2.0 million and $2.1 million as of December 31, 2019 and September 30, 2019, respectively, are included in property, equipment and improvements, net. Depreciation expense for these subscriber assets, which is included in cost of sales, was $0.3 million and $0.2 million for the three month periods ended December 31, 2019 and December 31, 2018, 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:



($ in thousands)	Three months ended December 31, 2019
Unearned revenue, beginning of period	$	5,025
Billings	9,847
Revenue recognized	(8,070		)
Unearned revenue, end of period	$	6,802

Remaining Transaction Price

Transaction price allocated to the remaining performance obligations represents contracted revenue that has not been recognized. This includes unearned revenue and unbilled amounts that will be recognized as revenue in future periods. As of December 31, 2019 approximately $13.2 million of revenue is expected to be recognized from remaining performance obligations for subscription contracts. We expect to recognize revenue on approximately $8.4 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 seven years.